- Anodization of bismuth doped TiO2 nanotubes composite for photocatalytic degradation of phenol in visible light
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Bismuth doped TiO2 photocatalyst was synthesized in a one-step electrochemical anodization method. Bismuth nitrate Bi(NO3)3 was used as a bismuth source. The obtained samples were characterized by FE-SEM, XRD, EDX and XPS. The optimum synthesis conditions for bismuth doping were 1.0 M bismuth nitrate in an ethylene glycol electrolyte with anodization at 40 V for 2 h. Compared with undoped TiO2 nanotubes, bismuth doped TiO2 photocatalyst showed a higher photocatalytic activity by a factor of 4.0 for phenol degradation under visible light irradiation. The optimum phenol degradation using a photoelectrocatalytic method was observed at a 0.5 V external bias, and this degradation rate was 5.2 times faster than that observed for undoped TiO2 nanotubes. The doped bismuth TiO2 nanotubes are favorable for the separation of photo-induced electrons and holes, reducing the recombination of charges, and promoting the formation of hydroxyl radicals and superoxides that degrade phenol.
- Ali, Imran,Kim, Seu-Run,Kim, Sung-Pil,Kim, Jong-Oh
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- Mechanistic Study on Deoxydehydration and Hydrogenation of Methyl Glycosides to Dideoxy Sugars over a ReO x-Pd/CeO2Catalyst
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We found that nonprotected methyl glycosides with cis-vicinal OH groups could be converted to the corresponding methyl dideoxy glycosides by deoxydehydration and consecutive hydrogenation (DODH + HG) over a ReOx-Pd/CeO2 catalyst with gaseous H2. In the study, the reactivity of the methyl glycosides in DODH was clearly lower than that of simple cyclic vicinal diols, such as cis-1,2-cyclohexanediol and cis-1,2-cyclopentanediol, and the reactivity of the methyl glycosides was also different. Herein, we investigated the reactivity difference based on kinetic studies and density-functional theory (DFT) calculations. The kinetic studies suggest that the reactivity difference between the methyl glycosides and the simple diols is derived from the OH group of methyl glycosides except the cis-vicinal diols, and that the reactivity difference among the methyl glycosides will be associated with the configuration of the substituents adjacent to the cis-vicinal diols, while the reaction mechanism of DODH is suggested to be basically similar judging from almost the same reaction orders with respect to the substrate concentration and H2 pressure in all substrates. The adsorption and transition states of methyl α -l- rhamnopyranoside and methyl α-l-fucopyranoside, which have a large reactivity difference (methyl α-l-rhamnopyranoside? methyl α-l-fucopyranoside), were estimated by DFT calculations with ReOx/CeO2 as the active site of the ReOx-Pd/CeO2 catalyst, showing that the main difference is the activation energy in DODH of these substrates (65 kJ mol-1 for methyl α-l-rhamnopyranoside and 77 kJ mol-1 for methyl α-l-fucopyranoside), which was also supported by the results of Arrhenius plots (63 and 73 kJ mol-1 for methyl α-l-rhamnopyranoside and methyl α-l-fucopyranoside, respectively). The activation energy was influenced by the torsional angle of the substituents adjacent to the cis-vicinal OH groups, which is derived from the interaction of the OH group adjacent to the cis-vicinal OH groups and the surface hydroxy groups on CeO2.
- Cao, Ji,Hasegawa, Jun-Ya,Hosaka, Ryu,Nakagawa, Yoshinao,Nakayama, Akira,Tamura, Masazumi,Tomishige, Keiichi
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- Structure, activity, and selectivity of bimetallic Pd-Fe/SiO2 and Pd-Fe/Γ-Al2O3 catalysts for the conversion of furfural
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The conversion of furfural has been investigated in vapor and liquid phases over a series of supported monometallic Pd and bimetallic Pd-Fe catalysts. Over the monometallic Pd/SiO2 catalyst, the decarbonylation reaction dominates, yielding furan as the main product. By contrast, over the bimetallic Pd-Fe/SiO2 catalyst a high yield of 2-methylfuran is obtained with much lower yield to furan. Interestingly, changing the catalyst support affects the product distribution. For instance, using γ-Al2O3 instead of SiO2 as support of the bimetallic catalyst changed the dominant product from 2-methylfuran to furan. That is, Pd-Fe/γ-Al2O3 behaves more like monometallic Pd/SiO2 than bimetallic Pd-Fe/SiO2. A detailed characterization of the catalysts via XPS, XRD, and TEM indicated that a Pd-Fe alloy is formed on the SiO2 support but not on the γ-Al2O3 support. Theoretical density functional theory calculations suggest that on the Pd-Fe alloy binding of the furan ring to the surface is weakened compared to on pure Pd. This weakening disfavors the ring hydrogenation and decarbonylation paths, while the oxophilic nature of Fe atoms enhances the interaction of the C[dbnd]O and the OH groups with the metal surface, which favors the C[dbnd]O hydrogenation and C–O bond cleavage paths. The presence of the solvent has a less pronounced effect, but clearly has a stronger inhibition on C–C bond cleavage (decarbonylation to furan) than on C–O bond cleavage (hydrogenolysis to methylfuran).
- Pino, Natalia,Sitthisa, Surapas,Tan, Qiaohua,Souza, Talita,López, Diana,Resasco, Daniel E.
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- Insights into the Oxidation State and Location of Rhenium in Re-Pd/TiO2 Catalysts for Aqueous-Phase Selective Hydrogenation of Succinic Acid to 1,4-Butanediol as a Function of Palladium and Rhenium Deposition Methods
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ReOx-Pd/TiO2 catalysts prepared from different 2 wt %Pd/TiO2 catalysts using two protocols for the deposition of the Re promoter (successive impregnation and catalytic reduction) were characterized by different techniques to better understand the nature of the active and selective sites implied in the aqueous-phase hydrogenation of succinic acid to 1,4-butanediol. Regardless of the support and Re introduction method, it was established that varying amounts of Pd and Re were in very close proximity without electronic interaction in the reduced catalysts. A high fraction of Re always remained partially oxidized to generate a bimetallic catalyst that can provide the necessary bifunctional sites to enable the selective hydrogenolysis of the intermediate γ-butyrolactone to 1,4-butanediol. Depending on the method of promotion, the ReOx species that interact with Pd were deposited as clusters with different spatial Re-Re interactions.
- Ly, Bao Khanh,Tapin, Beno?t,Aouine, Mimoun,Delichere, Pierre,Epron, Florence,Pinel, Catherine,Especel, Catherine,Besson, Michèle
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- Hydrodeoxygenation of vicinal OH groups over heterogeneous rhenium catalyst promoted by palladium and ceria support
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Heterogeneous ReOx-Pd/CeO2 catalyst showed excellent performance for simultaneous hydrodeoxygenation of vicinal OH groups. High yield (> 99%), turnover frequency (300 h-1), and turnover number (10 000) are achieved in the reaction of 1,4-anhydroerythritol to tetrahydrofuran. This catalyst can be applied to sugar alcohols, and mono-alcohols and diols are obtained in high yields (≥ 85%) from substrates with even and odd numbers of OH groups, respectively. The high catalytic performance of ReOx-Pd/CeO2 can be assigned to rhenium species with + 4 or + 5 valence state, and the formation of this species is promoted by H2/Pd and the ceria support.
- Ota, Nobuhiko,Tamura, Masazumi,Nakagawa, Yoshinao,Okumura, Kazu,Tomishige, Keiichi
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- Hydrogenation of succinic acid to tetrahydrofuran (THF) over ruthenium-carbon composite (Ru-C) catalyst
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Ruthenium-carbon composite (Ru-XC) catalysts prepared by a single-step surfactant-templating method were pre-graphitized at different temperature (X = 200, 250, 300, 350, and 400 C), and they were applied to the liquid-phase hydrogenation of succinic acid to tetrahydrofuran (THF). The effect of pre-graphitization temperature on the catalytic performance of Ru-XC catalysts (X = 200, 250, 300, 350, and 400 C) was investigated. It was observed that Ru-XC composite catalysts showed different textural properties depending on pre-graphitization temperature. In the liquid-phase hydrogenation of succinic acid to tetrahydrofuran (THF), conversion of succinic acid and yield for THF showed volcano-shaped trends with respect to pre-graphitization temperature. In other words, an optimal pre-graphitization temperature was required to achieve maximum catalytic performance of Ru-XC catalysts. Yield for THF in the hydrogenation of succinic acid increased with decreasing ruthenium particle size of Ru-XC catalysts. Among the catalysts tested, Ru-300C, which had the smallest ruthenium particle size, showed the highest yield for THF.
- Hong, Ung Gi,Kim, Jeong Kwon,Lee, Joongwon,Lee, Jong Kwon,Song, Ji Hwan,Yi, Jongheop,Song, In Kyu
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- Photocatalytic hydrogenation of furan to tetrahydrofuran in alcoholic suspensions of metal-loaded titanium(IV) oxide without addition of hydrogen gas
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The use of metal co-catalysts broadens the application of photocatalytic reduction without the use of dihydrogen (H2) gas. We examined photocatalytic hydrogenation of furan, a representative heterocyclic compound and a compound derived from biomass, in alcoholic suspensions of metal-loaded titanium(iv) oxide (TiO2) under a H2-free condition and we found that furan was almost quantitatively hydrogenated to tetrahydrofuran with a high apparent quantum efficiency of 37% at 360 nm when palladium was used as a co-catalyst. Effects of different metal co-catalysts, different amounts of the co-catalyst, the type of TiO2, the type of alcohol, light wavelength and reusability for furan hydrogenation were investigated. Based on the results, the functions of TiO2 and the co-catalyst and the reaction process are discussed.
- Nakanishi, Kousuke,Tanaka, Atsuhiro,Hashimoto, Keiji,Kominami, Hiroshi
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- Importance of Zeolite Wettability for Selective Hydrogenation of Furfural over Pd@Zeolite Catalysts
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The metal-catalyzed selective hydrogenation of biomass-derived molecules is in great demand but is challenging due to the complex reaction pathways. Herein, we report a persuasive example for achieving selective hydrogenation of furfural over Pd catalysts by controllable sorption of molecules in zeolite micropores. The key to this success is fixation of Pd nanoparticles inside of silicalite-1 zeolite with controllable wettability (Pd@S-1-OH) by functionalizing silanol groups into the zeolite framework. In the hydrogenation of furfural as a model reaction, the Pd@S-1-OH catalyst with appropriate hydrophilicity exhibits extraordinary selectivity for the formation of furan, giving furan selectivity as high as >99.9% with a complete conversion of furfural, outperforming the conventional Pd nanoparticles supported on zeolite crystals (Pd/S-1) and S-1 zeolite fixed Pd catalysts without an artificially functionalized silanol group (Pd@S-1). The extraordinary performance of Pd@S-1-OH is reasonably attributed to the controllable diffusion of molecules within the hydrophilic zeolite micropores, which favors the adsorption of furfural and a series of byproducts but promotes the desorption of furan. Very importantly, Pd@S-1-OH is stable and gives the furan productivity of ～583.3 g gPd-1 day-1 in a continuous test.
- Wang, Chengtao,Liu, Zhiqiang,Wang, Liang,Dong, Xue,Zhang, Jian,Wang, Guoxiong,Han, Shichao,Meng, Xiangju,Zheng, Anmin,Xiao, Feng-Shou
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- The selectively regulated vapour phase dehydrogenation of 1,4-butanediol to γ-butyrolactone employing a copper-based ceria catalyst
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The growing pursuit of the viable application of γ-butyrolactone (GBL) as an industrially important product offers the possibility to use 1,4-butanediol (1,4-BDO) as a potential reactant. In this regard, different proportions of copper-based ceria catalysts (5, 10, 15, and 20CC) were synthesized using a wet impregnation method and their catalytic activities were tested for the vapour phase dehydrogenation of 1,4-BDO to GBL at temperatures from 240-300 °C. The synthesized copper-based ceria catalysts (5CC, 10CC, 15CC, and 20CC) were characterized using various analytical tools and the consequent results revealed that the activities of the CC catalysts were influenced by the physicochemical properties of the materials. In order to determine the influence of various supports on the catalytic activity, the addition of 10 wt% copper (Cu) to TiO2, Al2O3, ZnO, ZSM-5, and SBA-15 supports was carried out, and the respective influence on the catalytic activity was also experimentally established. The most outstanding catalytic activity was seen for the 10 wt% copper-based ceria catalyst, with a high conversion of 93% and selectivity of 98% at 240 °C. Factors like a high surface area, and better dispersion and basicity of active sites had a marked impact on the catalytic activity. Mechanistic analysis suggested that 1,4-BDO undergoes dehydrogenation over the copper surface to give 4-hydroxybutanal, followed by hemiacetylation and subsequent dehydrogenation to give GBL as the selective product. In terms of the stability of the catalysts, the 10 wt% copper-based ceria catalyst maintained a stable GBL selectivity of 98% for up to 7 h on-stream.
- Bhanushali, Jayesh T.,Prasad, Divya,Patil, Komal N.,Babu, Gurram Venkata Ramesh,Kainthla, Itika,Rao, Kamaraju Seetha Rama,Jadhav, Arvind H.,Nagaraja, Bhari Mallanna
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- In situ DRIFTS for the mechanistic studies of 1,4-butanediol dehydration over Yb/Zr catalysts
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To study the effect of acid-base properties of catalysts on 1,4-butanediol (BDO) dehydration to 3-buten-1-ol (BTO), Yb/Zr catalysts with different Yb content were synthesized by a wet impregnation method. The texture property, crystalline form and surface
- Mi, Rongli,Hu, Zhun,Yang, Bolun
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- Catalytic Dehydration of 1,4-Butanediol over Mg?Yb Binary Oxides and the Mechanism Study
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In this study, Mg?Yb binary oxides were synthesized using different MgO concentrations and investigated for the catalytic dehydration of 1,4-butanediol (BDO) into 3-buten-1-ol (BTO). The physicochemical properties of the catalysts were characterized by N
- Hu, Zhun,Mi, Rongli,Yang, Bolun,Yi, Chunhai
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- The Elimination Kinetics of Methoxyalkyl Chlorides in the Gas Phase. Evidence for Neighboring Group Participation
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The rates of elimination of 3-methoxy-1-chloropropane and 4-methoxy-1-chlorobutane have been determined in a seasoned, static reaction vessel over the temperature range of 410-490 deg C and the pressure range of 56-181 torr.The reactions are homogeneous and unimolecular, follow a first-order rate low, and are invariant to the presence of a twofold or greater excess of the radical chain inhibitor toluene.The overall rate coefficients are given by the following Arrhenius equations: for 3-methoxy-1-chloropropane, logk1(s-1)=(12.92+/-0.48)-(226.0+/-6.8) kJ mol-1(2.303RT)-1; for 4-methoxy-1-chlorobutane, logk1(s-1)=(12. 9+/-0.26)-(218.1+/-3.5) kJ mol-1(2.303RT)-1.The CH3O group in 4-methoxy-1-chlorobutane has been found to assist anchimerically the elimination reaction, where dehydrochlorination and tetrahydrofuran formation arise from an intimate ion pair type of mechanism.The partial rates for these parallel eliminations have been determined and reported.Participation of the CH3O in 3-methoxy-1-chloropropane is barely detected.The present results give further evidence of intimate ion pair mechanism through neighboring group perticipation in the gas-phase elimination of certain types of organic molecules.
- Chuchani, Gabriel,Martin, Ignacio
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- Palladium–Ruthenium Catalyst for Selective Hydrogenation of Furfural to Cyclopentanol
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Bimetallic Pd–Ru/C catalyst was shown to be much more active in the aqueous-phase hydrogenation of furfural (473 K, 8 MPa) in comparison with both Pd/C and Ru/C catalysts. The enhanced hydrogenation activity manifested itself as an increased yield of cyclopentanol (77%) at a complete conversion of furfural. The observed synergistic effect between palladium and ruthenium in the tested reaction can be related to changes in the electronic state and particle size of supported metals upon interaction with each other and the Pd–Ru alloy formation.
- Mironenko,Belskaya,Lavrenov,Likholobov
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- Selective hydrogenolysis of 2-furancarboxylic acid to 5-hydroxyvaleric acid derivatives over supported platinum catalysts
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The conversion of 2-furancarboxylic acid (FCA), which is produced by oxidation of furfural, to 5-hydroxyvaleric acid (5-HVA) and its ester/lactone derivatives with H2 was investigated. Monometallic Pt catalysts were effective, and other noble metals were not effective due to the formation of ring-hydrogenation products. Supports and solvents had a small effect on the performance; however, Pt/Al2O3 was the best catalyst and short chain alcohols such as methanol were better solvents. The optimum reaction temperature was about 373 K, and at higher temperature the catalyst was drastically deactivated by deposition of organic materials on the catalyst. The highest yield of target products (5-HVA, δ-valerolactone (DVL), and methyl 5-hydroxyvalerate) was 62%, mainly obtained as methyl 5-hydroxyvalerate (55% yield). The byproducts were mainly ring-hydrogenation compounds (tetrahydrofuran-2-carboxylic acid and its ester) and undetected ones (loss of carbon balance). The catalyst was gradually deactivated during reuses even at a reaction temperature of 373 K; however, the catalytic activity was recovered by calcination at 573 K. The reactions of various related substrates were carried out, and it was found that the O-C bond in the O-CC structure (1,2,3-position of the furan ring) is dissociated before CC hydrogenation while the presence and position of the carboxyl group (or methoxy carbonyl group) much affect the reactivity.
- Asano, Takehiro,Takagi, Hiroshi,Nakagawa, Yoshinao,Tamura, Masazumi,Tomishige, Keiichi
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- NMR-DETECTION OF INTERMEDIATES DURING HOMOGENEOUS HYDROGENATION OF DIENES USING PARAHYDROGEN
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1.The 1H-NMR spectra of the reaction products of hydrogenations using parahydrogen reveal information about intermediates and thus the reaction mechanism. 2.Due to its high signal enhancement the method is uniquely suited for reactions, where the catalyst itself becomes chemically modified.
- Bargon J.,Kandels, J.,Kating, P.,Thomas, A.,Woelk, K.
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- Catalytic conversion of furan to gasoline-range aliphatic hydrocarbons via ring opening and decarbonylation reactions catalyzed by Pt/γ-Al 2O3
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Conversion of furan in the presence of H2 catalyzed by Pt/γ-Al2O3 at 573 K and 1.4 bar leads to the formation of alkanes and alkenes, some in the gasolinerange, including C7 hydrocarbons, butenes, propene, and propane.
- Runnebaum, Ron C.,Nimmanwudipong, Tarit,Doan, Jonathan,Block, David E.,Gates, Bruce C.
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- Versatile dual hydrogenation-oxidation nanocatalysts for the aqueous transformation of biomass-derived platform molecules
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Carbon-supported Pd nanoparticles have been proved to be efficient dual hydrogenation-oxidation nanocatalysts in both the selective aqueous oxidation of benzyl alcohol and the hydrogenation of furfural in water under microwave irradiation. Nanocatalysts b
- Garcia-Suarez, Eduardo J.,Balu, Alina Mariana,Tristany, Mar,Garcia, Ana Beatriz,Philippot, Karine,Luque, Rafael
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- Hydro-Oxygenation of Furfural in the Presence of Ruthenium Catalysts Based on Al-HMS Mesoporous Support
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Ru-containing catalyst based on an Al-HMS mesoporous aluminosilicate was synthesized. The mesoporous support and the catalyst on its basis were characterized by the methods of low-temperature desorption/adsorption of nitrogen, temperature-programmed desorption of ammonia, transmission electron microscopy, X-ray photoelectron microscopy, and energy-dispersive X-ray fluorescence analysis. The synthesized catalyst was investigated in the hydrodeoxygenation of the model compound of bio-oil, furfural, in the presence of H2O. The reaction was carried out at initial hydrogen pressures of 1–7 MPa at 200°C–300°C temperature range. The results revealed that the synthesized catalyst displayed a high activity in the hydrotransformation of furfural. The conversion was 100% in 1 hr at a 5 MPa hydrogen pressure and 200°C.
- Roldugina,Shayakhmetov,Maksimov,Karakhanov
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- Dehydration of 1,5-pentanediol over bixbyite Sc2-xYb xO3 catalysts
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Vapor-phase dehydration of 1,4- and 1,5-alkanediols was investigated over three scandium ytterbium mixed oxides, Sc2-xYbxO 3 (x = 0.5, 1.0, and 1.5), to produce the corresponding unsaturated alcohols. In the dehydration of
- Sato, Fumiya,Sato, Satoshi
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- Entropies of organolithium aggregation based on measured microsolvation numbers
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The recent measurement (J. Am. Chem. Soc.2008, 130, 14179-14188) of the microsolvation numbers of monodentate, nonchelating ethereal donor ligands coordinating to the monomers and dimers of two sterically shielded =C(aryl)-Li compounds permits the determination of well-founded dimerization enthalpies (ΔH0) and entropies (ΔS0) from properly formulated equilibrium constants, which must include the concentrations of the free donor ligands. The monomers are found to dimerize endothermically (ΔH0 > 0) in [D8]toluene solution in the presence of the donor tBuOMe or THF, but only slightly exothermically (ΔH 0 = -0.5 kcal per mol of dimer) with the donor Et2O. The dimerization entropies ΔS0 (in cal mol-1 K -1) with the respective equivalents of released donor ligands are 7.2 and 11.0 (with 2 equiv of tBuOMe in the two cases), 6.1 (with 2 Et 2O), and 34.1 (with 4 THF). It is shown that the improper omission of microsolvation from the equilibrium constant (a usual practice when the ligand numbers are not known) can lead to contaminated aggregation entropies ΔSψ, which may deviate considerably from the true entropies ΔS0. A method is provided for estimating the required microsolvation numbers from 13C/Li NMR coupling constants 1JC,Li for less congested organolithium types whose coordinated and free donor ligands cannot be distinguished by NMR integration.
- Knorr, Rudolf,Menke, Thomas,Ferchland, Kathrin
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- Effects of Ligand Halogenation on the Electron Localization, Geometry and Spin State of Low-Coordinate (β-Diketiminato)iron Complexes
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This contribution explores the influences of incorporating electron-withdrawing CF3and halide groups into (β-diketiminato)iron complexes of tetrazene and isocyanide. The synthesis of a new halogenated β-diketimine (LCF3,ClH) was accomplished by two different methods, including a novel microwave-assisted synthesis that improves the yield of the difficult condensation. Treatment of an iron(II) complex of this ligand with reductant and azide gives two diiron complexes with novel tetrazenes as bridging ligands. Structural and M?ssbauer data show that the bridging tetrazene is a radical anion. The halogenation of the supporting ligand also influences iron(I) complexes of the type [LFe(CNtBu)2], which are low-spin and square-planar with alkyl substituents but high-spin and pseudotetrahedral with halogen substituents. DFT calculations suggest that the changes from halogenation come from a combination of steric and electronic effects, and that the electronic influence of ligand halogenation is minor.
- Bellows, Sarina M.,Brennessel, William W.,Holland, Patrick L.
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- Ortho-directed lithiation of ω-phenoxy alcohols
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ω-Phenoxy alcohols, PhO(CH2)(n)OH (n = 2-7), have been subjected to metalation with 2 equiv of n-butyllithium in tetrahydrofuran/methylcyclohexane solvent. Reaction of the resulting lithiated compounds with carbon dioxide (n = 2-7), benzaldehyde (n = 2-6), benzophenone (n = 2, 3), dimethylformamide (n = 2), ethyl formate (n = 2), and chlorodiphenylphosphine (n = 3) afforded the corresponding ortho- substituted hydroxyalkoxybenzenes in yields ranging from 45 to 83%. The synthesis is also reported of five new bis[o-(ω-hydroxyalkoxy)phenyl]mercury compounds (n = 2-6), four crystal structures of which have been determined.
- Salteris, Constantinos S.,Kostas, Ioannis D.,Micha-Screttas, Maria,Heropoulos, George A.,Screttas, Constantinos G.,Terzis, Aris
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- Displacement of the THF solvent molecule from (η5-C5H5)Mn(CO)2THF by simple two electron donor ligands: Evidence for a dissociative mechanism and determination of the Mn-THF bond strength
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The reaction between CpMn(CO)2THF (Cp=η5-C5H5, THF=tetrahydrofuran) and nitrogen containing ligands is studied in THF solution. In all cases the products of the reaction are the known CpMn(CO)2L complexes (L=piperidine, 4-acetylpyridine). The reaction of the solvated complex with both ligands studied proceeds through a purely dissociative mechanism. In good agreement with previous thermochemical measurements, kinetic analysis yields an average value of 24.0±3.0 kcal mol-1 for the CpMn(CO)2-THF bond dissociation energy. The results of the present study clarify the relationship between metal-solvent bond strengths obtained by kinetic methods and those obtained by thermochemical measurements.
- Coleman, Jodi E.,Dulaney, Kim E.,Bengali, Ashfaq A.
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- Catalytic transfer hydrogenation/hydrogenolysis for reductive upgrading of furfural and 5-(hydroxymethyl)furfural
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The sequential transfer hydrogenation/hydrogenolysis of furfural and 5-hydroxymethylfurfural to 2-methylfuran and 2,5-dimethylfuran was studied over in situ reduced, Fe2O3-supported Cu, Ni, and Pd catalysts, with 2-propanol as hydrogen donor. The remarkable activity of Pd/Fe 2O3 in both transfer hydrogenation/hydrogenolysis is attributed to a strong metal-support interaction. Selectivity towards hydrogenation, hydrogenolysis, decarbonylation, and ring-hydrogenation products is shown to strongly depend on the Pd loading. A significant enhancement in yield to 62%, of 2-methylfuran and 2-methyltetrahydrofuran was observed under continuous flow conditions.
- Scholz, David,Aellig, Christof,Hermans, Ive
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- Synthesis of common-sized heterocyclic compounds by intramolecular cyclization over halide cluster catalysts
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Five- to seven-membered common-sized heterocyclic compounds containing an oxygen, sulfur, or nitrogen were synthesized by the intramolecular condensation of α,ω-hydroxy, mercapto, or amino alkanes, respectively, over halide cluster complexes as a thermally stable molecular solid weak acid catalyst in the gas phase at temperatures ≥150 °C. From ω- mercapto and ω-amino alcohols, cyclic sulfides and amines were obtained, respectively. These unimolecular reactions are thermodynamically and kinetically favored.
- Nagashima, Sayoko,Sasaki, Tomoaki,Kamiguchi, Satoshi,Chihara, Teiji
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- One-pot synthesis of 1-butylpyrrolidine and its derivatives from aqueous ammonia and 1,4-butandiol over CuNiPd/ZSM-5 catalysts
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The synthesis of 1-butylpyrrolidine and its derivatives (1-butylpyrrolidine with a little of 1-butenylpyrrolidines) was developed via a one-pot method from ammonia and 1,4-butandiol. Here, the product of 1-butylpyrrolidine was emphatically investigated, and the yield was 76% under the optimized conditions. Such a route was realized through successive N-alkylation using aqueous ammonia as the nitrogen source over the CuNiPd/ZSM-5 catalyst, which was prepared by a simple incipient wetness method. In this route, 1,4-butandiol not only participated in the formation of the N-heterocycle, but also acted as an alkylating reagent. This work offers a straightforward, economical route for 1-butylpyrrolidine and its derivatives. This journal is
- Long, Yan,Liu, Shimin,Ma, Xiangyuan,Lu, Liujin,He, Yude,Deng, Youquan
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- Liquid phase chemo-selective catalytic hydrogenation of furfural to furfuryl alcohol
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Novel Cu:Zn:Cr:Zr based catalysts were developed for the hydrogenation of furfural to furfuryl alcohol. Physio-chemical characterizations of the catalysts were performed by using XRD, BET, FTIR, TPR, NH3-TPD, ICP-MS, SEM, TEM, CO-chemisorption, and XANES techniques. Among all the catalysts prepared, the catalysts Cu(3):Zn(2):Cr(1):Zr(3) and Cu(3):Zn(2):Cr(1):Zr(4), referred as Cat-C and Cat-D, respectively are the best ones to demonstrate high activity and selectivity profile. Cat-C and Cat-D exhibited 100% conversion and 96% selectivity at 170 ± 2 °C and 2 MPa of hydrogen pressure. The role of constituent metals in the catalyst was delineated. Incorporation of Zn increases the activity for furfural conversion whereas Zr contributes significantly to the selectivity of furfuryl alcohol. It was also found that Zr loading not only increases the acidity of the catalyst but also helps in the dispersion of metallic Cu. The particle size of metallic Cu was found to be in the range of 17-19 nm as confirmed by TEM, XRD and CO chemisorption techniques. XANES analysis confirmed the presence of copper in Cu0 and Cu 2+ oxidation states in Cat-C (freshly reduced) and Cat-C (fresh), respectively. Hydrogenation of furfural to furfuryl alcohol follows a pseudo-first order reaction with an the apparent activation energy of 24.4 kcal/mol. Cat-C was recycled at least 4 times for the hydrogenation of furfural with no loss of activity and selectivity when compared to the fresh catalyst.
- Sharma, Rajesh V.,Das, Umashankar,Sammynaiken, Ramaswami,Dalai, Ajay K.
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- Shape and ligand effect of palladium nanocrystals on furan hydrogenation
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The Pd nanocrystals, including cubes, octahedra and wire, were prepared by shape-controlled solution phase reduction. The shape-dependent effect of Pd, and the effect of residual halogen ions and PVP, were investigated in selective hydrogenation of furan to tetrahydrofuran (THF). It was found that the residual halogen ions and PVP on the surface of Pd nanocrystals possibly reduced the hydrogenation activity and in turn it prevented the further reaction such as ring opening, so high selectivity towards THF was achieved even at high temperature. The 5-fold twinned wire displayed poor activity in furan hydrogenation due to a large amount of strongly adsorbed iodide ion residues covering most of the Pd active sites. An appropriate PVP residue is necessary, which can effectively maintain the shape and size stability of the Pd nanocube and octahedron, although the residual PVP partially blocks active Pd sites and reduces the activity for furan hydrogenation. The Pd nanocube enclosed by {100} facets exhibited about two times higher turnover frequency and lower apparent activation energy compared to the octahedron enclosed by {111} facets, suggesting a significant shape-dependent effect.
- Sun, Changyong,Cao, Zhou,Wang, Jiandian,Lin, Liangbiao,Xie, Xiaowei
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- Interfacial effect of Pd supported on mesoporous oxide for catalytic furfural hydrogenation
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Highly dispersed Pd is loaded onto different types of mesoporous oxide supports to investigate the synergetic metal-support effect in catalytic furfural (FAL) hydrogenation. Ordered mesoporous Co3O4, MnO2, NiO, CeO2, and Fe2O3 are prepared by the nanocasting and the supported Pd on mesoporous oxide catalysts are obtained by the chemical reduction method. It is revealed that mesoporous oxides play an important role on Pd dispersion as well as the redox behavior of Pd, which determines the final FAL conversion. Among the catalysts used, Pd/Co3O4 shows the highest conversion in FAL hydrogenation and distinct product selectivity toward 2-methylfuran (MF). While FAL is converted via two distinct pathways to produce either furfuryl alcohol (FA) via aldehyde hydrogenation or MF via hydrogenolysis, MF as a secondary product is derived from FA via the hydrogenolysis of C–O over the Pd/Co3O4 catalyst. It is revealed that FAL is hydrogenated to FA preferentially on the Pd surface; then the secondary hydrogenolysis to MF from FA is further promoted at the interface between Pd and Co3O4. We confirm that the reaction pathway over Pd/Co3O4 is totally different from other catalysts such as Pd/MnO2, which produces FA dominantly. The characteristics of the mesoporous oxides influence the Pd-oxide interfaces, which determine the activity and selectivity in FAL hydrogenation.
- Lee, Hojeong,Nguyen-Huy, Chinh,Jeong Jang, Eun,Lee, Jihyeon,Yang, Euiseob,Lee, Man Sig,Kwak, Ja Hun,An, Kwangjin
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- Liquid phase hydrodeoxygenation of furfural over laponite supported NiPMoS nanocatalyst: Effect of phosphorus addition and laponite support
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Unsupported and laponite supported NiPMoS catalysts were prepared under the hydrothermal method and investigated for liquid-phase hydrodeoxygenation of furfural in a high-pressure batch reactor at 423 ?K ? 463 ?K under 20 ?bar H2 pressure. The reaction significantly produced 94% of furfural conversion with 75% yield of 2-MF on NiPMoS catalyst whereas, NiPMoS/Lap catalyst exhibited 28% of 2-MF yield with complete conversion at 463 ?K under 20 ?bar H2 pressure in toluene solvent. The influence of process parameters such as reaction temperature, reactant volume, catalyst compositions, and hydrogen pressure on furfural conversion and product yield was investigated in detail. The high reactivity and synergetic effect of the NiPMoS catalyst are due to added phosphorus, which has a profound influence on the structure of the catalyst, thereby increasing surface acidity, basicity, hydrogen consumption, and a number of MoS2 fringes and the dispersion of MoS2 on the surface of the support. The catalysts were characterized based on HRTEM, H2, CO2, and NH3 TPD, FT–IR, FT–Raman, DRS UV–Vis, XRD, N2–physisorption, and TGA. Recyclability, N2–physisorption, and XRD results confirm the stability and practical applicability of the catalyst for industrial applications.
- Krishnan, P. Santhana,Umasankar,Tamizhdurai,Mangesh,Shanthi
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- Chromium-free Cu?Mg/γ-Al2O3-an active catalyst for selective hydrogenation of furfural to furfuryl alcohol
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Development of a chromium (Cr)-free hydrogenation catalyst is very important to replace the existing hazardous Cr based catalyst used in the furfural hydrogenation to furfuryl alcohol. Herein, we report synthesis of well-dispersed copper nanoparticles supported on hydrothermally stable magnesium doped alumina (Cu?Mg/γ-Al2O3) for selective hydrogenation of furfural to furfuryl alcohol. The prepared catalyst was characterized by X-ray Photoelectron Spectroscopy (XPS), Auger Electron Spectroscopy (AES), Powder X-ray Diffraction (PXRD), Surface Area Analysis (SAA), High Resolution-Transmission Electron Microscopy (HR-TEM), Temperature Programmed Reduction/Desorption (TPR/TPD) and Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) to understand textural properties of the catalyst. The prepared catalyst was found to be highly active and selective with 99% conversion of furfural and 94% selectivity for furfuryl alcohol under solvent free conditions at 443.15 K and 2 MPa of hydrogen pressure. It was also observed that the Cu?Mg/γ-Al2O3 catalyst is reusable (up to six runs) while maintaining its high activity and selectivity (≥94%) in the hydrogenation of furfural to furfuryl alcohol. This journal is
- Arundhathi, Racha,Newalkar, Bharat L.,Reddy, Panyala Linga,Samanta, Chanchal
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- Synthesis and reactivity of naphthalene complexes of ytterbium
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The complexes formulated as C10H8Ybx(THF)y (X = 1-2, y = 2-4) have been obtained as black pyrophoric powders by reactions of anhydrous ytterbium diiodide with a lithium naphthalide in THF.The reactions of samarium and europium iodide
- Bochkarev, M. N.,Trifonov, A. A.,Fedorova, E. A.,Emelyanova, N. S.,Basalgina, T. A.,et al.
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- Mechanism of formation of tetrahydrofuran in the catalytic hydrogenation of dialkyl succinates
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The kinetics of formation of tetrahydrofuran from dibutyl succinate were studied. The mechanism of catalytic hydrogenation of dialkyl succinates was found to involve consecutive formation of ?-butyrolactone, butane-1,4-diol, and tetrahydrofuran. Parameters of kinetic equations that properly describe the system of concurrent and consecutive reactions were determined.
- Timofeev,Bazanov,Zubritskaya
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- Heterogeneous CaO-ZrO2 acid-base bifunctional catalysts for vapor-phase selective dehydration of 1,4-butanediol to 3-buten-1-ol
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A series of acid-base bifunctional CaO-ZrO2 catalysts was prepared simply by the impregnation method and evaluated for the vapour-phase dehydration of 1,4-butanediol (BDO). The effects of CaO content and calcination temperature on the catalytic properties of the CaO-ZrO2 catalysts were investigated. It was found that the catalyst with 12.5 wt% CaO and at a calcination temperature of 650°C exhibited favorable catalytic performance and good stability for the selective dehydration of BDO to 3-buten-1-ol (BTO). The maximum BTO selectivity and BDO conversion reached 68.9% and 94.6%, respectively. The formation of by-product, THF, was markedly suppressed. These catalysts were characterized by N2 physisorption, XRD, FT-IR spectra, NH3-TPD and CO2-TPD. The results indicated that the CaO-ZrO2 catalysts showed higher basicity density and similar acidity density compared to unmodified ZrO2 due to the formation of Ca-O-Zr Hetero-linkage by CaO introduction. The catalytic performance depended on the coexistence of acidic and basic sites on the surface of catalysts.
- Zhang, Qian,Zhang, Yin,Li, Haitao,Gao, Chunguang,Zhao, Yongxiang
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- Furfural hydrodeoxygenation (HDO) over silica-supported metal phosphides – The influence of metal–phosphorus stoichiometry on catalytic properties
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The gas-phase hydrodeoxygenation (HDO) of furfural, a model compound for bio-based conversion, was investigated over transition metal phosphide catalysts. The HDO activity decreases in the order Ni2P ≈ MoP > Co2P ≈ WP ? Cu3P > Fe2P. Nickel phosphide phases (e.g., Ni2P, Ni12P5, Ni3P) are the most promising catalysts in the furfural HDO. Their selectivity to the gasoline additives 2-methylfuran and tetrahydro-2-methylfuran can be adjusted by varying the P/Ni ratio. The effect of P on catalyst properties as well as on the reaction mechanism of furfural HDO were investigated in depth for the first time. An increase of the P stoichiometry weakens the furan-ring/catalyst interaction, which contributes to a lower ring-opening and ring-hydrogenation activity. On the other hand, an increasing P content does lead to a stronger carbonyl/catalyst interaction, i.e., to a stronger η2(C, O) adsorption configuration, which weakens the C1[sbnd]O1 bond (Scheme 1) in the carbonyl group and enhances the carbonyl conversion. Phosphorus species can also act as Br?nsted acid sites promoting C1[sbnd]O1 (Scheme 1) hydrogenolysis of furfuryl alcohol, hence contributing to higher production of 2-methylfuran.
- Lan, Xuefang,Pestman, Robert,Hensen, Emiel J.M.,Weber, Thomas
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- Preparation of Er2O3 nanorod catalyst without using organic additive and its application to catalytic dehydration of 1,4-butanediol
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Er2O3 nanorods were successfully prepared with hydrothermal treatment without using organic additives such as surfactant, fatty acid, or alcohol. Er2 O3 nanorods were obtained under high temperature and/or long reaction times. Er2O3 nanorods mainly exposed {440} and {400} facets on the surface. Er2O3 nanorods showed excellent catalytic activity compared to commercial Er2O3 nanoparticles in the dehydration of 1,4-butanediol to produce 3-buten-1-ol.
- Sato, Fumiya,Yamada, Yasuhiro,Sato, Satoshi
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- Colloidal and Nanosized Catalysts in Organic Synthesis: XXIV. Study of Hydrogenation of Furan and Its Derivatives in the Presence of MgO-Supported Nickel and Cobalt Nanoparticles
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Abstract: The processes of hydrogenation of furan and its derivatives (2-methylfuran, furfuryl alcohol, and furfural) in plug-flow type reactor under atmospheric hydrogen pressure at 20–220°С in the presence of supported nickel nanoparticles prepared via chemical reduction have been investigated. It has been found that nickel nanoparticles supported on magnesium oxide surface are the most reactive and stable under the considered conditions. This catalyst allows the corresponding hydrogenation products with 100percent yield and complete conversion of the substrate.
- Gendler, T. A.,Mokhov, V. M.,Nebykov, D. N.,Popov, Yu. V.,Shemet, V. V.,Shirkhanyan, P. M.
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- Conversion of 1,4-Butanediol to Furan Compounds on Cobalt Catalysts in the Liquid Phase
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The transformation of 1,4-butanediol on cobalt catalysts applied to kieselguhr in the liquid phase under periodic and continuous conditions was investigated.When the reaction is carried out under periodic conditions, the principal reaction products are 2,3-dihydrofuran, tetrahydrofuran, and γ-butyrolactone.An increase in the selectivity of the formation of 2,3-dihydrofuran as the temperature is raised was established. 2,3-Dihydrofuran is obtained in 63-73 mole percent yields under optimum conditions. 2,3-Dihydrofuran is converted to tetrahydrofuran when the process is carried out under continuous conditions on a tableted cobalt catalyst.
- Geiman, I. I.,Bulenkova, L. F.,Lazdin'sh, A. A.,Veinberg, A. K.,Slavinskaya, V. A.,Avots, A. A.
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- Investigating hydrogenation and decarbonylation in vapor-phase furfural hydrotreating over Ni/SiO2 catalysts: Propylene production
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Furfural can be mass-produced from lignocellulose biomass and can be a platform chemical for producing valuable chemicals. In this study, we examine Ni/SiO2 catalysts for the conversion of furfural under a hydrogen atmosphere. The reactivity an
- Chen, Szu-Hua,Tseng, Ya-Chun,Yang, Sheng-Chiang,Lin, Shawn D.
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- Reduction of Dicarboxylic Acid Anhydride with 2-Propanol over Hydrous Zirconium Oxide
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The reduction of dicarboxylic acid anhydrides with 2-propanol proceeded efficiently over hydrous zirconium oxide to give the corresponding lactones and cyclic ethers.Secondary and primary alcohols, with the exception of methanol, are able to act as hydride donors in this reduction.The reduction proceeded as nearly second order concerning the concentration of 2-propanol and minus order concerning that of acid anhydride.These results suggest that the reduction was preferred under lower concentrations of acid anhydride and higher concentrations of 2-propanol.The selectivity of lactone or ether could be changed by the reaction temperature or the molar ratio of dicarboxylic acid anhydride to alcohol.
- Takahashi, Kyoko,Shibagaki, Makoto,Matsushita, Hajime
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- Efficient aqueous hydrogenation of biomass platform molecules using supported metal nanoparticles on Starbons
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An efficient protocol for the hydrogenation of platform molecules (e.g. succinic acid) in aqueous environments using supported metal nanoparticles on polysaccharide derived mesoporous carbonaceous materials is reported for the first time.
- Luque, Rafael,Clark, James H.,Yoshida, Kenta,Gai, Pratibha L.
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- Hydrogenation of succinic acid to tetrahydrofuran (THF) over rhenium catalyst supported on H2SO4-treated mesoporous carbon
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Mesoporous carbon (MC) prepared by a surfactant-templating method was treated with different H2SO4 concentration (X = 0, 0.2, 0.4, 0.6, 0.8, and 1.0 M) for use as a support (MC-X) for rhenium catalyst. Rhenium catalysts supported on H2SO4-treated mesoporous carbons (Re/MC-X) were then prepared by an incipient wetness impregnation method, and they were applied to the liquid-phase hydrogenation of succinic acid to tetrahydrofuran (THF). The effect of H2SO4 treatment on the physicochemical properties and catalytic activity of Re/MC-X catalysts (X = 0, 0.2, 0.4, 0.6, 0.8, and 1.0) was investigated. It was observed that MC-X supports showed different pore characteristics depending on H2SO 4 concentration. As a result, Re/MC-X catalysts showed different rhenium particle size. In the liquid-phase hydrogenation of succinic acid to tetrahydrofuran (THF), conversion of succinic acid and yield for THF showed volcano-shaped curves with respect to H2SO4 concentration. Thus, an optimal H2SO4 concentration was required to achieve maximum catalytic performance of Re/MC-X. Yield for THF in the hydrogenation of succinic acid increased with decreasing rhenium particle size of Re/MC-X catalysts. Among the catalysts tested, Re/MC-0.4 with the smallest rhenium particle size showed the highest yield for THF.
- Hong, Ung Gi,Park, Hai Woong,Lee, Joongwon,Hwang, Sunhwan,Yi, Jongheop,Song, In Kyu
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- PRODUCTION METHOD OF CYCLIC COMPOUND
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PROBLEM TO BE SOLVED: To provide an industrially simple production method of a cyclic compound. SOLUTION: A production method of a cyclic compound includes a step to obtain a reduced form (B) by reducing an unsaturated bond in a ring structure of an aromatic compound (A) by means of catalytic hydrogenation of the aromatic compound (A) or its salt using palladium carbon as a catalyst under a normal pressure, in which the aromatic compound (A) has one or more ring structures selected from a group consisting of a five membered-ring, a six membered-ring, and a condensed ring of the five membered-ring or the six membered-ring with another six membered-ring, a hetero atom can be included in the ring structure, and the aromatic compound (A) can have one or two side chains bonded to the ring structure and does not have any carbon-carbon triple bond in the side chain. SELECTED DRAWING: None COPYRIGHT: (C)2021,JPOandINPIT
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Paragraph 0057-0058; 0062-0063
(2021/05/05)
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- H2-Free Selective Dehydroxymethylation of Primary Alcohols over Palladium Nanoparticle Catalysts
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The dehydroxymethylation of primary alcohols is a promising strategy to transform biomass-derived oxygenates into hydrocarbon fuels. In this study, a novel, highly efficient, and reusable heterogeneous catalyst system was established for the H2-free dehydroxymethylation of primary alcohol using cerium oxide-supported palladium nanoparticles (Pd/CeO2). A wide range of aliphatic and aromatic alcohols including biomass-derived alcohols were converted into the corresponding one-carbon shorter hydrocarbons in high yields in the absence of any additives, accompanied by the production of H2 and CO. Pd/CeO2 was easily recovered from the reaction mixture and reused, retaining its high activity, thus, providing a simple and sustainable methodology to produce hydrocarbon fuels from biomass-derived oxygenates.
- Yamaguchi, Sho,Kondo, Hiroki,Uesugi, Kohei,Sakoda, Katsumasa,Jitsukawa, Koichiro,Mitsudome, Takato,Mizugaki, Tomoo
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p. 1135 - 1139
(2020/12/29)
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- Method for synthesizing cyclopropanecarboxaldehyde from 1,4-butanediol
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The invention relates to a method for synthesizing cyclopropanecarboxaldehyde from 1,4-butanediol. The method has the advantages of accessible raw materials, low cost and simple technique, can implement one-step reaction, has high efficiency, and can implement continuous operation.
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Paragraph 0049-0053; 0059-0063; 0069-0073
(2021/03/13)
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- Deoxygenation of primary amides to amines with pinacolborane catalyzed by Ca[N(SiMe3)2]2(THF)2
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Deoxygenative reduction of amides is a challenging but favorable synthetic method of accessing amines. In the presence of a catalytic amount of Ca[N(SiMe3)2]2(THF)2, pinacolborane (HBpin) could efficiently reduce a broad scope of amides, primary amides in particular, into corresponding amines. Functional groups and heteroatoms showed good tolerance in this process of transformation, and a plausible reaction mechanism was proposed.
- Gong, Mingliang,Guo, Chenjun,Jiang, Linhong,Luo, Yunjie,Yu, Chong
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supporting information
p. 1201 - 1206
(2021/05/29)
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- Vapor-phase dehydration of 1,4-butanediol to 1,3-butadiene over Y2Zr2O7 catalyst
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Vapor-phase catalytic dehydration of 1,4-butanediol (1,4-BDO) was investigated over Y2O3-ZrO2 catalysts. In the dehydration, 1,3-butadiene (BD) together with 3-buten-1-ol (3B1OL), tetrahydrofuran, and propylene was produced depending on the reaction conditions. In the dehydration over Y2O3-ZrO2 catalysts with different Y contents at 325°C, Y2Zr2O7 with an equimolar ratio of Y/Zr showed high selectivity to 3B1OL, an intermediate to BD. In the dehydration at 360°C, a BD yield higher than 90% was achieved over the Y2Zr2O7 calcined at 700°C throughout 10 h. In the dehydration of 3B1OL over Y2Zr2O7, however, the catalytic activity affected by the calcination temperature is roughly proportional to the specific surface area of the sample. The highest activity of Y2Zr2O7 calcined at 700 °C for the BD formation from 1,4-BDO is explained by the trade-off relation in the activities for the first-step dehydration of 1,4-BDO to 3B1OL and for the second-step dehydration of 3B1OL to BD. The higher reactivity of 3B1OL than saturated alcohols such as 1-butanol and 2-butanol suggests that the C=C double bond of 3B1OL induces an attractive interaction to anchor the catalyst surface and promotes the dehydration. A probable mechanism for the one-step dehydration of 1,4-BDO to BD was discussed.
- Matsuda, Asami,Matsumura, Yoshitaka,Sato, Satoshi,Yamada, Yasuhiro
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- Method for preparing epoxybutane by using small organic molecules to catalyze butene in green and efficient manner
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The invention discloses a method for preparing epoxybutane by using small organic molecules to catalyze butene in a green and efficient manner. The method comprises the following steps of by taking butene as a raw material, adding an organic solvent and a catalyst, taking isobutyraldehyde as a co-reducing agent, and taking oxygen as an oxidizing agent, preparing the epoxybutane at room temperature under the reaction pressure of 0.1-4.5 MPa. The catalyst is selected from at least one of a cyclic organic nitroxide free radical precursor or a compound with the structure as shown in the following formulas (I), (II), (III) or (IV); and R1, R2 and R3 in the formula are independently selected from hydrogen atoms, alkyl groups, cycloalkyl groups, aryl groups, heterocyclic rings, hydroxyl groups, nitryl groups or halogens, or at least two of R2, R3 and R4 form rings. The method has the advantages of simple process, mild conditions, high yield and selectivity of epoxybutane, and good industrial application prospects.
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Paragraph 0050-0085
(2021/08/25)
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- Ring-Closing Metathesis of Aliphatic Ethers and Esterification of Terpene Alcohols Catalyzed by Functionalized Biochar
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Functionalized biochars, renewable carbon materials prepared from waste biomass, can catalyze transformations of a range of oxygen-containing substrates via hydrogen-bonding interactions. Good conversions (up to 75.2 %) to different O-heterocycles are obtained from ring-closing C?O/C?O metathesis reactions of different aliphatic ethers under optimized conditions using this heterogeneous, metal-free, and easy separable catalyst. The diversity in the sorts of O-containing feedstocks is further demonstrated by the utilization of functionalized biochar to promote the esterification of terpene alcohols, an important reaction in food and flavor industries. Under the optimized conditions, full conversions to various terpene esters are obtained. Moreover, both of the reactions studied herein are performed under neat conditions, thus increasing the overall sustainability of the process described.
- Kerton, Francesca M.,MacQuarrie, Stephanie L.,Vidal, Juliana L.,Wyper, Olivia M.
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supporting information
p. 6052 - 6056
(2021/12/10)
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- TiO2supported Ru catalysts for the hydrogenation of succinic acid: Influence of the support
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Succinic acid is a valuable biomass-derived platform molecule, which can be further catalytically converted into many industrially relevant molecules such as γ-butyrolactone, 1,4-butanediol or tetrahydrofuran. The influence of the support nature on both the activity of Ru/TiO2 catalysts and the selectivity pattern in the hydrogenation of succinic acid was investigated, with focus on the metal-support interaction, the crystallographic structure of the TiO2 support and the supported Ru nanoparticle size features. We showed that the catalyst activity was related to both the Ru particle size and the metal support interaction, those features being induced by the presence of the rutile phase within the TiO2 support and by the preparation method of the supported Ru particles. The rutile phase not only favors the formation of small Ru particles but also promotes stronger metal-support interaction compared with the anatase polymorph. Strong interactions between metal and support can also be formed via thermal reduction in contrast to low-temperature direct chemical reduction. Interestingly, a low temperature solar photon-assisted synthesis method facilitates very high succinic acid conversion, by enabling the stabilization of 1.8 nm small-size Ru nanoparticles in the absence of any rutile phase within the TiO2 support. This journal is
- Brzezinska, Magdalena,Keller, Nicolas,Louven, Yannik,Niemeier, Johannes,Palkovits, Regina,Ruppert, Agnieszka M.
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p. 6860 - 6869
(2020/11/09)
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- Can Heteroarenes/Arenes Be Hydrogenated Over Catalytic Pd/C Under Ambient Conditions?
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Hydrogenation of over a dozen aromatic compounds, including both heteroarenes and arenes, over palladium on carbon (Pd/C, 1–100 molpercent) with H2-balloon pressure at room temperature is reported. Analyses using pyridine as a model substrate revealed that acetic acid was the best solvent, as using only 1 molpercent Pd/C provided piperidine quantitatively. Substrate scope analysis and density functional theory calculations indicated that reaction rates are highly dependent on frontier molecular orbital characteristics and the steric bulkiness of substituents. Moreover, the established method was used for the concise synthesis of the anti-Alzheimer drug donepezil (Aricept?).
- Tanaka, Nao,Usuki, Toyonobu
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p. 5514 - 5522
(2020/07/24)
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- One-pot reductive amination of carboxylic acids: a sustainable method for primary amine synthesis
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The reductive amination of carboxylic acids is a very green, efficient and sustainable method for the production of (bio-based) amines. However, with current technology, this reaction requires two to three reaction steps. Here, we report the first (heterogeneous) catalytic system for the one-pot reductive amination of carboxylic acids to amines, with solely H2 and NH3 as the reactants. This reaction can be performed with relatively cheap ruthenium-tungsten bimetallic catalysts in the green and benign solvent cyclopentyl methyl ether (CPME). Selectivities of up to 99% for the primary amine could be achieved at high conversions. Additionally, the catalyst is recyclable and tolerant for common impurities such as water and cations (e.g. sodium carboxylate).
- Coeck, Robin,De Vos, Dirk E.
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supporting information
p. 5105 - 5114
(2020/08/25)
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- Structural evolution of ZIF-67-derived catalysts for furfural hydrogenation
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Zeolitic imidazolate framework-67 (ZIF-67) can be converted to metallic Co nanoparticles supported on N-doped carbon (Co/NC) through reduction. However, its unique properties, including extremely high surface area, isoreticular pore structure, and regular metal–organic network, disappear after high-temperature (>500 °C) reduction. Aggregated CoOx particles reduce the number of surface-active sites, resulting in poor catalytic activity. If the original ZIF-67 structure is maintained after the high-temperature reduction, promoting the uniform distribution of active sites in the porous carbon, the catalytic performance can be further improved. Herein, the correlation between the catalytic furfural hydrogenation performance, Co/NC morphology, and oxidation state of Co was investigated as a function of the H2 reduction temperature and time. The reduction of ZIF-67 at 400 °C for 6 h yields a highly dispersed Co/NC catalyst, while preserving the overall morphology. The resulting Co/NC-400-6 catalyst exhibits the highest activity, promoting high selectivity toward 2-methylfuran. The product selectivity can be further altered by incorporating Cu into ZIF-67 to produce furfuryl alcohol. With proper H2 treatment to minimize the damage to the intrinsic surface area and pore structure, metal–organic frameworks can be utilized as high-performance heterogeneous catalysts by maximizing the distribution of active sites.
- An, Kwangjin,Lee, Jae Hwa,Lee, Jun Gyeong,Moon, Hoi Ri,Song, Kyung,Yang, Euiseob,Yoon, Sinmyung
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p. 302 - 312
(2020/11/20)
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- Olefin reaction in the catalyst and the olefin production
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PROBLEM TO BE SOLVED: To provide a catalyst for obtaining an olefin in high selectivity with a vicinal diol as a raw material.SOLUTION: A catalyst for olefination reaction for use in a reaction to produce an olefin by a reaction of a polyol, having two adjacent carbon atoms each having a hydroxy group, with hydrogen comprises: a carrier; at least one oxide selected from the group consisting of oxides of the group 6 elements and oxides of the group 7 elements supported on the carrier; and at least one metal selected from the group consisting of silver, iridium, and gold supported on the carrier.SELECTED DRAWING: None
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Paragraph 0109; 0118-0119; 0124-0125;0129-0132; 0134; ...
(2020/10/31)
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- Highly dispersed Pd catalysts supported on various carbons for furfural hydrogenation
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Furfural (FAL), one of the important platform molecules derived from lignocellulosic biomass, can be converted into valuable chemicals such as furfuryl alcohol or cyclopentanone via hydrogenation. While carbon materials have been used as versatile catalyst supports for FAL hydrogenation, systematic studies on the structure of the catalytic performances are lacking. In this work, we prepare various types of carbon supports to investigate the impact of carbon structures for Pd-catalyzed FAL hydrogenation. Mesoporous carbons, including CMK-3, CMK-5, CMK-8, and MSU-F-C, as well as carbon nanotube and Vulcan XC are used as carbon supports. For the preparation of highly dispersed Pd-supported carbon (Pd/C) catalysts, chemical reduction by sodium borohydride is applied, in which trisodium citrate plays a critical role in anchoring small Pd clusters on the carbons. In the liquid-phase hydrogenation of FAL, CMK-5 with the largest surface area and hexagonal hollow tubular framework is proven to be the most efficient carbon support for Pd/C catalysts, with the highest conversion of FAL in both 2-propanol (100percent) and water (86.4percent) solvents. It is also demonstrated that the product selectivity in FAL hydrogenation over various Pd/C catalysts is changed dramatically depending on the type of solvent. The Pd/C catalysts exhibit similar fractions of product distributions containing furfuryl alcohol, cyclopentanol, tetrahydrofurfuryl alcohol, and minor products in 2-propanol. However, the production of cyclopentanone is increased when water is used as a solvent.
- Lee, Jihyeon,Woo, Jinwoo,Nguyen-Huy, Chinh,Lee, Man Sig,Joo, Sang Hoon,An, Kwangjin
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- Effects of a forming process on the properties and structure of RANEY-Ni catalysts for the hydrogenation of 1,4-butenediol
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Three commercial Ni-Al alloys formed by a vacuum atomization method (NAV), atmospheric atomization method (NAA) and high-temperature melting method (NAH) were leached by 10 wt% NaOH solution to prepare three RANEY-Ni catalysts (RNAV, RNAA and RNAH, correspondingly). The effects of a forming process on the structure of Ni-Al alloys and the corresponding RANEY-Ni catalysts were investigated via XRD, XPS, SEM, TEM, NH3-TPD, N2 adsorption-desorption and EDX-mapping studies. Also, the as-prepared RANEY-Ni catalysts were evaluated via the hydrogenation of 1,4-butenediol (BED) to produce 1,4-butanediol (BDO). The results showed that the specific surface areas and surface morphologies of the Ni-Al alloys present significant differences. Meanwhile, the RNAA sample presented a comparatively regular morphology, similar to a small piece of sugar cane. The weak and medium acid peak areas of the RNAA catalyst were lower than those of the other samples. RNAV showed higher weak and medium acid peak areas, demonstrating the higher number of acid centers on the surface of the catalyst. The surface of the RNAA catalyst obtained from NAA contained more active component-Ni, about 90 wt% on the surface, and the specific surface area of the sample was 75 times that of its precursor Ni-Al alloy powder (NAA). The evaluation results present that the RNAA catalyst shows better hydrogenation performance, with BED conversion of 100%, both BDO selectivity and yield of 46.11%.
- Fan, Xing,Gao, Xianlong,Ma, Fengyun,Mo, Wenlong,Noritatsu, Tsubaki,Wu, Hongli
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p. 5516 - 5524
(2020/02/22)
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- Efficient one-pot conversion of furfural into 2-methyltetrahydrofuran using non-precious metal catalysts
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2-methyltetrahydrofuran, a biomass-derived chemical, is an important solvent with broad applications in organic chemistry. In this study, one-pot conversion of furfural into 2-methyltetrahydrofuran over non-precious metal catalysts was achieved by two-stage packing in a single reactor. The first stage converted furfural into 2-methylfuran over Co-based catalysts, and the second stage converted 2-methylfuran into 2-methyltetrahydrofuran over Ni-based catalysts. In order to reveal the reaction pathway and mechanism of this process, the hydrogenation reactions of 2-methylfuran, furfuryl alcohol, and tetrahydrofurfuryl alcohol were also carefully investigated. It is discovered that the conversion of furfural into 2-methylfuran could be catalyzed by Lewis acid sites, which was confirmed by a correlation between 2-methylfuran production rate and Lewis acid site density. Also, a mechanism on the direct conversion of furfural into 2-methylfuran without forming furfuryl alcohol as the intermediate is proposed. The experimental results of 2-methylfuran, furfuryl alcohol, and tetrahydrofurfuryl alcohol hydrogenation/hydrodeoxygenation over various catalysts provided valuable information on the future design of 2-methyltetrahydrofuran catalyst.
- Jia, Xinxin,Li, Cuiqing,Liu, Ping,Song, Yongji,Sun, Luyang,Wang, Hong,Zhang, Chen,Zhang, Wei
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- Experimental study of speciation and mechanistic implications when using chelating ligands in aryl-alkynyl Stille coupling
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Neutral palladium(ii) complexes [Pd(Rf)X(P-L)] (Rf = 3,5-C6Cl2F3, X = Cl, I, OTf) with P-P (dppe and dppf) and P-N (PPh2(bzN)) ligands have chelated structures in the solid-state, except for P-L = dppf and X = Cl, were chelated and dimeric bridged structures are found. The species present in solution in different solvents (CDCl3, THF, NMP and HMPA) have been characterised by 19F and 31P{1H} NMR and conductivity studies. Some [Pd(Rf)X(P-L)] complexes are involved in equilibria with [Pd(Rf)(solv)(P-L)]X, depending on the solvent and X. The ΔH° and ΔS° values of these equilibria explain the variations of ionic vs. neutral complexes in the range 183-293 K. Overall the order of coordination strength of solvents and anionic ligands is: HMPA ? NMP > THF and I-, Cl- > TfO-. This coordination preference is determining the complexes participating in the alkynyl transmetalation from PhCCSnBu3 to [Pd(Rf)X(P-L)] (X = OTf, I) in THF and subsequent coupling. Very different reaction rates and stability of intermediates are observed for similar complexes, revealing neglected complexities that catalytic cycles have to deal with. Rich information on the evolution of these Stille systems after transmetalation has been obtained that leads to proposal of a common behaviour for complexes with dppe and PPh2(bzN), but a different evolution for the complexes with dppf: this difference leads the latter to produce PhCCRf and black Pd, whereas the two former yield PhCCRf and [Pd(CCPh)(SnBu3)(dppe)] or [Pd(CCPh)(SnBu3){PPh2(bzN)}]. This journal is
- Espinet, Pablo,Gallego, Ana M.,Marcos-Ayuso, Guillermo,Martínez-Ilarduya, Jesús M.,Martin-Alvarez, Jose M.,Pe?as-Defrutos, Marconi N.
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supporting information
p. 11336 - 11345
(2020/09/03)
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- Cascade conversion of furancarboxylic acid to butanediol diacetate over Pd/C and La(OTf)3 catalytic system
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The conversion of biomass to a high value-added product 1, 4-butanediol (BDO) and its derivatives is of great economic significance. In this work, furancarboxylic acid (FCA) was adopted as the raw material to prepare BDO. The one-pot synthesis of 1, 4-butanediol diacetate (BDA) has been successfully prepared from FCA with metal triflates and Pd/C catalysts. The effect of reaction conditions was investigated and the reaction routes was systematically studied by 1H-NMR and GC. The tandem catalytic process from FCA to BDA mainly underwent three stages. Firstly, FCA was hydrogenated to tetrahydrofurfuric acid (THFCA) by Pd/C. Afterwards, THFCA was decarbonylated to form oxonium ions with metal triflates. Then the oxonium ions was rapidly hydrogenated to form tetrahydrofuran (THF) by Pd/C. Ultimately, THF was ring-opening esterified to BDA by metal triflates. This novel synthesis method of BDO from FCA provides a promising protocol for broadening the application of common biomass substrates.
- Deng, Jin,Fu, Yao,Gong, Baoxiang,Zhou, Gongyu,Zhu, Rui
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- Method for preparing epoxybutane
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The disclosure relates to a method for preparing epoxybutane. The method comprises the following steps: a, in the presence of acid or alkaline, a raw material mixture containing 1-butene, methanol andan oxidizing agent touches an oxidation catalyst for a reaction to obtain a second mixture containing the methanol and butanediol; b, the second mixture obtained in step a is separated to obtain thebutanediol; and c, the butanediol obtained in step b touches a dehydration catalyst for a dehydration reaction to obtain the epoxybutane. The method solves the problem that products in a line of preparing the epoxybutane by taking the 1-butene as a raw material and the methanol as a solvent are difficult to separate, and the high-purity epoxybutane can be prepared.
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Paragraph 0050-0086
(2020/12/08)
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- METHOD FOR PRODUCING CYCLIC ETHER
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A method for producing a cyclic ether represented by formula (2) includes reacting a 2-hydroxy cyclic ether, represented by formula (1), with hydrogen in the presence of a catalyst.
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Paragraph 0048-0052; 0057-0059
(2020/12/14)
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- Dialkyl Ether Formation at High-Valent Nickel
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In this article, we investigated the I2-promoted cyclic dialkyl ether formation from 6-membered oxanickelacycles originally reported by Hillhouse. A detailed mechanistic investigation based on spectroscopic and crystallographic analysis revealed that a putative reductive elimination to forge C(sp3)-OC(sp3) using I2 might not be operative. We isolated a paramagnetic bimetallic NiIII intermediate featuring a unique Ni2(OR)2 (OR = alkoxide) diamond-like core complemented by a μ-iodo bridge between the two Ni centers, which remains stable at low temperatures, thus permitting its characterization by NMR, EPR, X-ray, and HRMS. At higher temperatures (>-10 °C), such bimetallic intermediate thermally decomposes to afford large amounts of elimination products together with iodoalkanols. Observation of the latter suggests that a C(sp3)-I bond reductive elimination occurs preferentially to any other challenging C-O bond reductive elimination. Formation of cyclized THF rings is then believed to occur through cyclization of an alcohol/alkoxide to the recently forged C(sp3)-I bond. The results of this article indicate that the use of F+ oxidants permits the challenging C(sp3)-OC(sp3) bond formation at a high-valent nickel center to proceed in good yields while minimizing deleterious elimination reactions. Preliminary investigations suggest the involvement of a high-valent bimetallic NiIII intermediate which rapidly extrudes the C-O bond product at remarkably low temperatures. The new set of conditions permitted the elusive synthesis of diethyl ether through reductive elimination, a remarkable feature currently beyond the scope of Ni.
- Le Vaillant, Franck,Reijerse, Edward J.,Leutzsch, Markus,Cornella, Josep
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supporting information
p. 19540 - 19550
(2020/12/01)
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- Iridium complex catalytic ring lactone hydrogenation [...] method
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The present invention provides one kind of iridium complex catalytic ring lactone hydrogenation [...] method, organic chemical technical field. The present invention is to ring lactone as raw materials, iridium complex as the catalyst hydrogenation reaction, in particular in accordance with the following steps: that the intrauterine lactone, iridium complex, the hydrogen gas as a reducing agent, the hydrogen reduction reaction, iridium complexes and ring lactone mass ratio is 0.00001 - 0.1; a hydrogen pressure of 1.0 - 10.0 mpa; the reaction temperature is 90 - 150 °C, the reaction time is: 0.5 - 72 h. The beneficial effects of the present invention: simple reaction operation, product selectivity and easy separation.
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Paragraph 0028-0029
(2019/07/04)
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- Preparation of Highly Active Monometallic Rhenium Catalysts for Selective Synthesis of 1,4-Butanediol from 1,4-Anhydroerythritol
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1,4-Butanediol can be produced from 1,4-anhydroerythritol through the co-catalysis of monometallic mixed catalysts (ReOx/CeO2+ReOx/C) in the one-pot reduction with H2. The highest yield of 1,4-butanediol was over 80 %, which is similar to the value obtained over ReOx–Au/CeO2+ReOx/C catalysts. Mixed catalysts of CeO2+ReOx/C showed almost the same performance, giving 89 % yield of 1,4-butanediol. The reactivity trends of possible intermediates suggest that the reaction mechanism over ReOx/CeO2+ReOx/C is similar to that over ReOx–Au/CeO2+ReOx/C: deoxydehydration (DODH) of 1,4-anhydroerythritol to 2,5-dihydrofuran over ReOx species on the CeO2 support with the promotion of H2 activation by ReOx/C, isomerization of 2,5-dihydrofuran to 2,3-dihydrofuran catalyzed by ReOx on the C support, hydration of 2,3-dihydrofuran catalyzed by C, and hydrogenation to 1,4-butanediol catalyzed by ReOx/C. The reaction order of conversion of 1,4-anhydroerythritol with respect to H2 pressure is almost zero and this indicates that the rate-determining step is the formation of 2,5-dihydrofuran from the coordinated substrate with reduced Re in the DODH step. The activity of ReOx/CeO2+ReOx/C is higher than that of ReOx–Au/CeO2+ReOx/C, which is probably related to the reducibility of ReOx/C and the mobility of the Re species between the supports. High-valent Re species such as Re7+ on the CeO2 and C supports are mobile in the solvent; however, low-valent Re species, including metallic Re species, have much lower mobility. Metallic Re and cationic low-valent Re species with high reducibility and low mobility can be present on the carbon support as a trigger for H2 activation and promoter of the reduction of Re species on CeO2. The presence of noble metals such as Au can enhance the reducibility through the activation of H2 molecules on the noble metal and the formation of spilt-over hydrogen over noble metal/CeO2, as indicated by H2 temperature-programmed reduction. The higher reducibility of ReOx–Au/CeO2 lowers the DODH activity of ReOx–Au/CeO2+ReOx/C in comparison with ReOx/CeO2+ReOx/C by restricting the movement of Re species from C to CeO2.
- Wang, Tianmiao,Tamura, Masazumi,Nakagawa, Yoshinao,Tomishige, Keiichi
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p. 3615 - 3626
(2019/07/15)
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- Interface synergy between IrOx and H-ZSM-5 in selective C–O hydrogenolysis of glycerol toward 1,3-propanediol
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Site-selective deoxygenation of hydroxyl groups represents essential processes to access valuable functionalized bio-based compounds with industrial potential. One of the challenging tasks in this context is to convert biodiesel-derived glycerol in the presence of abundant water directly to 1,3-propanediol (1,3-PDO), a key component of the emerging polymer industry. Herein, a monometallic iridium supported on H-ZSM-5 in the absence of Re oxophilic metal oxides was prepared via grinding-assisted impregnation procedures and attempted as an effective and recyclable catalyst for the aqueous-phase selective hydrogenolysis of glycerol toward 1,3-PDO in the absence of acid additives. The results revealed the necessity to control the Ir domain dispersions, Ir0/Ir3+ ratio and the amounts of overall acid/Br?nsted acid sites. Activity depended linearly on the amount of overall and Br?nsted acid sites, and 1,3-PDO selectivity increased in the presence of Ir-induced Br?nsted acid sites, denoted as Ir-O(H)-H-ZSM-5. We speculate that Ir-O(H)-H-ZSM-5 are generated by the interfacial synergistic interaction between IrOx and H-ZSM-5 through hydrogen spillover and reverse hydrogen spillover according to the reported literatures. The reaction mechanism to elucidate the role of Ir-O(H)-H-ZSM-5 sites in glycerol hydrogenolysis was also postulated based on extensive characterization and catalytic reaction results.
- Wan, Xiaoyue,Zhang, Qi,Zhu, Mingming,Zhao, Yi,Liu, Yongmei,Zhou, Chunmei,Yang, Yanhui,Cao, Yong
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p. 339 - 350
(2019/07/03)
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- TiO2-supported molybdenum carbide: An active catalyst for the aqueous phase hydrogenation of succinic acid
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TiO2-supported Mo carbides “MoC/TiO2” were prepared by impregnation of Mo salt followed by temperature programmed reduction-carburization using 20% v/v C2H6/H2. Catalysts were characterized by XRD, XPS, TEM, STEM, ICP, Raman, BET, and carbon elemental analysis. The catalytic activity was evaluated for aqueous phase hydrogenation of succinic acid at 160–240 °C, and 90–150 bar of H2 in batch reactor. MoC/TiO2 is active for this reaction. The main products after 24 h are γ-butyrolactone, and more remarkably butyric acid. These intermediates are then converted to tetrahydrofuran, butanol, 1,4-butanediol and butane. The reaction conditions (temperature, pressure) do not impact the products distribution. A larger amount of butyric acid is formed when catalysts were synthesized with a higher gas hourly space velocity. The deactivation observed while recycling the catalyst was mainly attributed to a decrease in the amounts of carbidic molybdenum and carbidic carbon, as demonstrated by XPS analysis.
- Abou Hamdan, Marwa,Loridant, Stéphane,Jahjah, Mohamad,Pinel, Catherine,Perret, Noémie
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- Chemoselective reduction of heteroarenes with a reduced graphene oxide supported rhodium nanoparticle catalyst
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Rhodium nanoparticles immobilized on reduced graphene oxide were obtained from the microwave-induced thermal decomposition of Rh6(CO)16 in the ionic liquid [bmim][BF4] (bmim = 1-butyl-3-methylimidazolium cation) in the absence of additional stabilizing agents. The resulting rhodium nanoparticles are 99%, without interfering with other reducible groups, and with high conversions. Related catalysts prepared using conventional thermal heating were prepared for comparison purposes and were found to be considerably less active.
- Karakulina, Alena,Gopakumar, Aswin,Fei, Zhaofu,Dyson, Paul J.
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p. 5019 - 5097
(2018/10/17)
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- Polysilane-Immobilized Rh-Pt Bimetallic Nanoparticles as Powerful Arene Hydrogenation Catalysts: Synthesis, Reactions under Batch and Flow Conditions and Reaction Mechanism
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Hydrogenation of arenes is an important reaction not only for hydrogen storage and transport but also for the synthesis of functional molecules such as pharmaceuticals and biologically active compounds. Here, we describe the development of heterogeneous Rh-Pt bimetallic nanoparticle catalysts for the hydrogenation of arenes with inexpensive polysilane as support. The catalysts could be used in both batch and continuous-flow systems with high performance under mild conditions and showed wide substrate generality. In the continuous-flow system, the product could be obtained by simply passing the substrate and 1 atm H2 through a column packed with the catalyst. Remarkably, much higher catalytic performance was observed in the flow system than in the batch system, and extremely strong durability under continuous-flow conditions was demonstrated (>50 days continuous run; turnover number >3.4 × 105). Furthermore, details of the reaction mechanisms and the origin of different kinetics in batch and flow were studied, and the obtained knowledge was applied to develop completely selective arene hydrogenation of compounds containing two aromatic rings toward the synthesis of an active pharmaceutical ingredient.
- Miyamura, Hiroyuki,Suzuki, Aya,Yasukawa, Tomohiro,Kobayashi, Shu
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supporting information
p. 11325 - 11334
(2018/09/06)
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- One-pot catalytic selective synthesis of 1,4-butanediol from 1,4-anhydroerythritol and hydrogen
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A physical mixture of ReOx-Au/CeO2 and carbon-supported rhenium catalysts effectively converted 1,4-anhydroerythritol to 1,4-butanediol with H2 as a reductant. The combination of these two catalysts in a one-pot reaction dramatically increased the selectivity of 1,4-butanediol as well as the conversion of 1,4-anhydroerythritol. The yield of 1,4-butanediol reached ～90%, which is the highest yield from erythritol and 1,4-anhydroerythritol so far, furthermore, at a relatively low reaction temperature of 413 K. This reaction involves the ReOx-Au/CeO2-catalyzed deoxydehydration of 1,4-anhydroerythritol to 2,5-dihydrofuran and ReOx/C-catalyzed successive isomerization, hydration and reduction reactions of 2,5-dihydrofuran.
- Wang, Tianmiao,Liu, Sibao,Tamura, Masazumi,Nakagawa, Yoshinao,Hiyoshi, Norihito,Tomishige, Keiichi
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supporting information
p. 2547 - 2557
(2018/06/18)
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- Palladium/Graphitic Carbon Nitride (g-C3N4) Stabilized Emulsion Microreactor as a Store for Hydrogen from Ammonia Borane for Use in Alkene Hydrogenation
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Direct hydrogenation of C=C double bonds is a basic transformation in organic chemistry which is vanishing from simple practice because of the need for pressurized hydrogen. Ammonia borane (AB) has emerged as a hydrogen source through its safety and high hydrogen content. However, in conventional systems the hydrogen liberated from the high-cost AB cannot be fully utilized. Herein, we develop a novel Pd/g-C3N4 stabilized Pickering emulsion microreactor, in which alkenes are hydrogenated in the oil phase with hydrogen originating from AB in the water phase, catalysed by the Pd nanoparticles at the interfaces. This approach is advantageous for more economical hydrogen utilization over conventional systems. The emulsion microreactor can be applied to a range of alkene substrates, with the conversion rates achieving >95 % by a simple modification.
- Han, Chenhui,Meng, Peng,Waclawik, Eric R.,Zhang, Chao,Li, Xin-Hao,Yang, Hengquan,Antonietti, Markus,Xu, Jingsan
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supporting information
p. 14857 - 14861
(2018/10/24)
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- METHOD FOR PRODUCING TETRAHYDROFURANE, 1,4-BUTANEDIOL OR GAMMA-BUTYROLACTONE
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Processes for preparing tetrahydrofuran and/or butane-1,4-diol and/or gamma-butyrolactone are provided, including a process for preparing tetrahydrofuran (THF) from succinic acid that has been obtained by conversion of biomass, by conversion of the succinic acid to succinic anhydride, and hydrogenation of the succinic anhydride, with removal of certain secondary components.
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Paragraph 0108-0112; 0113
(2018/02/03)
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- METHOD FOR PRODUCING 1,3-BUTADIENE FROM 1,4-BUTANEDIOL
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A method for producing 1,3-butadiene from a 1,4-butanediol feedstock: One step for esterification of 1,4-butanediol,One step for pyrolysis of 1,4-butanediol diester, producing butadiene.
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Paragraph 0096-0098
(2018/03/01)
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- Selective Conversion of CO2 into Isocyanate by Low-Coordinate Iron Complexes
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Discovery of the mechanisms for selective transformations of CO2 into organic compounds is a challenge. Herein, we describe the reaction of low-coordinate Fe silylamide complexes with CO2 to give trimethylsilyl isocyanate and the corresponding Fe siloxide complex. Kinetic studies show that this is a two-stage reaction, and the presence of a single equivalent of THF influences the rates of both steps. Isolation of a thermally unstable intermediate provides mechanistic insight that explains both the effect of THF in this reaction, and the way in which the reaction achieves high selectivity for isocyanate formation.
- Broere, Dani?l L. J.,Mercado, Brandon Q.,Holland, Patrick L.
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supporting information
p. 6507 - 6511
(2018/05/04)
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- In situ MnOx/N-doped carbon aerogels from cellulose as monolithic and highly efficient catalysts for the upgrading of bioderived aldehydes
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Herein, we report a sustainable route to in situ synthesize a monolithic MnOx/N-doped carbon aerogel catalyst (Mn-NCA) by pyrolysing MnO(OH)2-cellulose aerogel precursors based on an alkali-urea aqueous system. The as-obtained Mn-NCA showed highly efficient catalytic activity for the transfer hydrogenation of a broad range of biomass-derived aldehydes, yielding 90-100% conversion and 64-100% selectivity to the corresponding alcohols under mild conditions in an oven without agitation. A combination of controlled experiments and detailed characterization studies indicated that the superior performance of Mn-NCA is attributed to the monolithic three-dimensional (3D) hierarchical porous architecture and the synergistic effects between homogeneously dispersed MnOx nanoparticles (NPs) and urea-derived basic sites. The monolithic feature of Mn-NCA exhibits superior dispersibility and separability compared to conventional centrifugation and filtration techniques in a powdery catalytic system. Moreover, a possible reaction mechanism is proposed. Our work provides a new method for developing highly efficient monolithic catalysts from renewable biopolymers for biomass valorization.
- Zhou, Shenghui,Chen, Guixian,Feng, Xiao,Wang, Ming,Song, Tao,Liu, Detao,Lu, Fachuang,Qi, Haisong
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p. 3593 - 3603
(2018/08/17)
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- At room temperature in water: efficient hydrogenation of furfural to furfuryl alcohol with a Pt/SiC-C catalyst
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Selective hydrogenation of furfural (FAL) to furfuryl alcohol (FOL) is challenging because of many side reactions. The highly selective hydrogenation of FAL to FOL can be achieved over a Pt catalyst supported on nanoporous SiC-C composites even at room temperature in water. A Pt/SiC-C-200-H2 catalyst, which had a Pt loading of 3 wt% and was reduced in flowing hydrogen at 500 °C after calcination in air at 200 °C for 2 h, furnished complete FAL conversion and over 99% selectivity to FOL at 25 °C under 1 MPa of hydrogen in water. The kinetic behaviour of the selective hydrogenation of FAL to FOL with the 3 wt% Pt/SiC-C-200-H2 catalyst was also investigated and the turnover frequency (TOF) reached 1148 h?1. Moreover, the Pt/SiC-C catalyst is more active than other Pt catalysts supported on ordered mesoporous carbon CMK-3, activated carbon, periodic mesoporous silica SBA-15 or Al2O3. Detailed characterization using XRD, N2-sorption, SEM, TEM and XPS techniques reveals that the striking performance of the Pt/SiC-C catalyst can be attributed to the optimal metal-support interaction and the interfacial effect.
- Wang, Guimei,Yao, Ruihua,Xin, Huiyue,Guan, Yejun,Wu, Peng,Li, Xiaohong
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p. 37243 - 37253
(2018/11/26)
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- Zeolite-Encapsulated Pt Nanoparticles for Tandem Catalysis
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Encapsulation of metal nanoparticles in a zeolite matrix is a promising route to integrate multiple sequential reactions into a one-pot and one-step tandem catalytic reaction. We report a cationic polymer-assisted synthetic strategy to encapsulate Pt nanoparticles (NPs) into MFI zeolites. Degrees of encapsulation of Pt NPs in the synthesized catalysts exceeding 90% were demonstrated via kinetic studies of model reactions involving substrates with different molecular dimensions. HZSM-5 zeolite-encapsulated Pt NPs are able to selectively mediate the tandem aldol condensation and hydrogenation of furfural and acetone to form hydrogenated C8 products with a combined yield of 87%. In contrast, hydrogenation and decarbonylation of furfural dominate on Pt NPs supported on HZSM-5 at otherwise identical conditions. The high selectivity toward the tandem reaction on the encapsulated catalyst is attributed to the distribution of metal and acid sites, which limits the access of furfural to Pt sites and promotes the acid-catalyzed aldol condensation. This is the first demonstration that the product distribution in a tandem reaction is manipulated by tailoring the architecture of catalytic materials via encapsulation.
- Cho, Hong Je,Kim, Doyoung,Li, Jing,Su, Dong,Xu, Bingjun
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supporting information
p. 13514 - 13520
(2018/10/20)
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