- 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 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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- 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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- 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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p. 181 - 193
(2021/02/27)
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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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- 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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p. 291 - 300
(2020/03/05)
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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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- 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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- 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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- 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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p. 41120 - 41126
(2020/11/23)
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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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- 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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supporting information
p. 16708 - 16712
(2020/10/27)
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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 0109-0111; 0129-0132; 0134-0135; 0150
(2020/10/31)
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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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- 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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- 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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- 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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- 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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p. 1306 - 1315
(2019/11/03)
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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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p. 6133 - 6145
(2019/11/20)
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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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p. 11968 - 11983
(2019/08/07)
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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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p. 138 - 151
(2019/01/04)
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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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- 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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- 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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- 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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- 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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- 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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p. 339 - 346
(2018/06/11)
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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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p. 474 - 481
(2018/01/17)
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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 C?O Hydrogenolysis of Erythritol over Supported Rh-ReOx Catalysts in the Aqueous Phase
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Bimetallic Rh-ReOx (Re/Rh molar ratio 0.4–0.5) catalysts supported on TiO2 and ZrO2 were prepared by the successive impregnation of dried and calcined unreduced supported Rh catalysts. Their catalytic performances were evaluated in the hydrogenolysis of erythritol to butanetriols (BTO) and butanediols (BDO) in aqueous solution at 150–240 °C under 30–120 bar H2. The activity depended on the nature of the support, and the highest selectivity to BTO and BDO at 80 % conversion was 37 and 29 %, respectively, in the presence of 3.7 wt %Rh-3.5 wt %ReOx/ZrO2 at 200 °C under 120 bar. The characterization of the catalysts by CO chemisorption, TEM with energy-dispersive X-ray spectroscopy, thermogravimetric analysis with MS, and X-ray photoelectron spectroscopy suggests a different distribution and reducibility of Re species over the supported Rh nanoparticles, which depends on the support.
- Said, Achraf,Da Silva Perez, Denilson,Perret, Noémie,Pinel, Catherine,Besson, Michèle
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p. 2768 - 2783
(2017/07/28)
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- Method for catalytic conversion of furfural
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The invention relates to a method for catalytic conversion of furfural, which comprises taking furfural and a methanol aqueous solution as raw materials and heating to carry out a reduction reaction on the furfural in the presence of a loaded type nickel-based catalyst, so as to prepare a furfural converted product comprising furan and/or methyl furan as main components. As the methanol aqueous solution is adopted as a solvent and a hydrogen supply reagent of the reaction, the situation that a series of cost and security problems of transportation, storage and operation are caused due to great consumption of external hydrogen can be avoided, methods of catalyst preparation and furfural conversion are simple, the used reagent is non-toxic, operation conditions are mild, the cost reduction and the production benefit improvement can be facilitated, and thus the method has good industrial prospects.
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Paragraph 0045-0046
(2017/08/26)
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- Directing Reaction Pathways through Controlled Reactant Binding at Pd–TiO2 Interfaces
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Recent efforts to design selective catalysts for multi-step reactions, such as hydrodeoxygenation (HDO), have emphasized the preparation of active sites at the interface between two materials having different properties. However, achieving precise control over interfacial properties, and thus reaction selectivity, has remained a challenge. Here, we encapsulated Pd nanoparticles (NPs) with TiO2 films of regulated porosity to gain a new level of control over catalyst performance, resulting in essentially 100 % HDO selectivity for two biomass-derived alcohols. This catalyst also showed exceptional reaction specificity in HDO of furfural and m-cresol. In addition to improving HDO activity by maximizing the interfacial contact between the metal and metal oxide sites, encapsulation by the nanoporous oxide film provided a significant selectivity boost by restricting the accessible conformations of aromatics on the surface.
- Zhang, Jing,Wang, Bingwen,Nikolla, Eranda,Medlin, J. Will
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supporting information
p. 6594 - 6598
(2017/05/29)
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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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- Nickel Phosphide/Silica Catalysts for the Gas-Phase Hydrogenation of Furfural to High–Added–Value Chemicals
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A series of Ni2P-based catalysts supported on a commercial silica with a metallic Ni loading of 5–20 wt. % and an initial P/Ni molar ratio of 0–3 was prepared by incipient wetness impregnation. Catalyst precursors were reduced and characterized by using XRD, CO chemisorption, NH3 temperature-programmed desorption, N2 adsorption–desorption at ?196 °C, and X-ray photoelectron spectroscopy and then tested in the gas-phase hydrogenation of furfural. Almost full furfural conversion and a 2-methylfuran yield of 73 % can be achieved with the Ni2P-based catalyst with a Ni content of 15 wt. % at 190 °C after 5 h of time on stream. The high selectivity towards 2-methylfuran is attributed to both the high hydrogenating capacity of the metallic sites to lead to furfuryl alcohol and the presence of reduced P species that favor the hydrogenolysis process. However, catalysts undergo deactivation along the catalytic test because of the formation of carbonaceous deposits in the form of coke and adsorption of reactants and/or products.
- Jiménez-Gómez, Carmen P.,Cecilia, Juan A.,Moreno-Tost, Ramón,Maireles-Torres, Pedro
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p. 2881 - 2889
(2017/07/28)
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- Tetrabutylphosphonium Bromide Catalyzed Dehydration of Diols to Dienes and Its Application in the Biobased Production of Butadiene
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We report the use of the ionic liquid tetrabutylphosphonium bromide as a solvent and catalyst for dehydration of diols to conjugated dienes. This system combines stability, high reaction rates, and easy product separation. A reaction mechanism for the model compound 1,2-hexanediol is proposed and experimentally corroborated. This particular mechanism allows for the selective formation of conjugated dienes, in contrast with purely acidic catalysis. Next, the reaction is also performed on various other diols. As a first application, we assessed the biobased production of 1,3-butadiene. With 1,4-butanediol as the starting material, a 94% yield of butadiene was reached at 100% conversion.
- Stalpaert, Maxime,Cirujano, Francisco G.,De Vos, Dirk E.
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p. 5802 - 5809
(2017/09/15)
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- 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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- Vapor-phase catalytic dehydration of 1,4-butanediol to 3-buten-1-ol over modified ZrO2 catalysts
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Vapor-phase catalytic dehydration of 1,4-butanediol (1,4-BDO) was investigated over modified ZrO2catalysts. In the dehydration of 1,4-BDO over monoclinic ZrO2(m-ZrO2), an unsaturated alcohol, 3-buten-1-ol (3B1OL), was produced together with tetrahydrofuranand γ-butyrolactone. Among alkaline earth metal oxide modifiers, CaO with an appropriate content significantly enhanced the 3B1OL selectivity of m-ZrO2. The modification of CaO was more efficient over m-ZrO2than tetragonal ZrO2. CO2-TPD measurements reveal that CaO supported on m-ZrO2calcined at 800?°C or higher generated new basic sites, which are attributed from Ca-O-Zr hetero-linkages, for the effective formation of 3B1OL from 1,4-BDO. In order to create more Ca-O-Zr hetero-linkages on the m-ZrO2surface efficiently, additional ZrO2was loaded on m-ZrO2together with CaO via a co-impregnation method. At an appropriate weight ratio of CaO/ZrO2?=?7/2 loaded on m-ZrO2, both the 1,4-BDO conversion and the 3B1OL selectivity were enhanced greatly. Especially, the 3B1OL selectivity exceeded 90% at 350?°C.
- Duan, Hailing,Hirota, Tomoya,Ohtsuka, Shota,Yamada, Yasuhiro,Sato, Satoshi
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- Selective hydrogenation of unsaturated carbonyls by Ni-Fe-based alloy catalysts
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Ni-Fe alloy catalysts prepared by a simple hydrothermal method and subsequent H2 treatment exhibited the greatest activity and selectivity for the hydrogenation of biomass-derived furfural to furfuryl alcohol among the examined second metals, such as Al, Ga, In, Co, and Ti. This work reveals that the alloying of Ni and Fe is a key factor in achieving highly selective hydrogenation of the CO moiety in unsaturated carbonyl substrates. We found that decreasing the temperature of H2 treatment (i.e. decreasing the crystallite size), e.g. Ni-Fe(2)HT-573 K (TOF = 952 h-1), increased the activity compared to that over Ni-Fe(2)HT-673 (TOF = 375 h-1) for furfural hydrogenation. This result suggests that a low-coordinated Ni-Fe alloy was imperative for the catalytic cycle. Moreover, the effect of the metal/support interface was critical; despite the high catalytic performance of Ni-Fe/TiO2, Ni-Fe/Al2O3, and Ni-Fe/CeO2, Ni-Fe supported on SiO2, taeniolite, and hydrotalcite catalysts were ineffective. Vibrational studies using FT-IR measurement confirmed that furfural was physically adsorbed on the surface of the Ni-Fe alloy catalyst via an η1(O) configuration. The synthetic scope of the Ni-Fe catalytic system was very broad; various types of unsaturated carbonyls, such as unsaturated aromatics, unconjugated aliphatics, and a large substituent, were selectively converted into the corresponding unsaturated alcohols.
- Putro, Wahyu S.,Kojima, Takashi,Hara, Takayoshi,Ichikuni, Nobuyuki,Shimazu, Shogo
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p. 3637 - 3646
(2017/08/21)
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- Hydrogenation of dicarboxylic acids to diols over Re-Pd catalysts
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A Re-Pd/SiO2 (Re/Pd = 8) catalyst was applied to hydrogenation of dicarboxylic acids (succinic acid, glutaric acid and adipic acid) to diols. In the hydrogenation of dicarboxylic acids, ex situ liquid-phase (in only 1,4-dioxane solvent) reduced Re-Pd/SiO2 showed much higher activity than in situ liquid-phase (in the mixture of dicarboxylic acid and 1,4-dioxane) and gas-phase reduced ones, in which the in situ liquid-phase reduced catalyst has been reported to show good activity in the hydrogenation of monocarboxylic acids. High diol yields (71-89%) were achieved in the hydrogenation of dicarboxylic acids on the ex situ liquid-phase reduced catalyst at 413 K. Lactones and hydroxycarboxylic acids were first formed as intermediates in the reaction of C4-C5 and ≥C6 dicarboxylic acids, respectively. Characterization using XRD, XPS and XAS indicates that ex situ liquid-phase reduced catalysts with high activity contains comparable amounts of Re0 and Ren+ species, both of which have been reported to be necessary for good performance. The amount of Ren+ species on the in situ liquid-phase reduced catalysts is much larger than that of surface Re0 species. This result suggests that the presence of dicarboxylic acids suppresses the reduction of Re species to Re0 on the calcined catalysts while that of monocarboxylic acids does not, which leads to the low activity in the hydrogenation of dicarboxylic acids on in situ liquid-phase reduced catalysts.
- Takeda, Yasuyuki,Tamura, Masazumi,Nakagawa, Yoshinao,Okumura, Kazu,Tomishige, Keiichi
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p. 5668 - 5683
(2016/07/21)
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- Ga[OSi(OtBu)3]3·THF, a thermolytic molecular precursor for high surface area gallium-containing silica materials of controlled dispersion and stoichiometry
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The molecular precursor tris[(tri-tert-butoxy)siloxy]gallium, as the tetrahydrofuran adduct Ga[OSi(OtBu)3]3·THF (1), was synthesized via the salt metathesis reaction of gallium trichloride with NaOSi(OtBu)3. This complex serves as a model for isolated gallium in a silica framework. Complex 1 decomposes thermally in hydrocarbon solvent, eliminating isobutylene, water, and tert-butanol to generate high surface area gallium-containing silica at low temperatures. When thermal decomposition was performed in the presence of P-123 Pluronic as a templating agent the generated material displayed uniform vermicular pores. Textural mesoporosity was evident in untemplated material. Co-thermolysis of 1 with HOSi(OtBu)3 in the presence of P-123 Pluronic led to materials with Ga : Si ratios ranging from 1 : 3 to 1 : 50, denoted UCB1-GaSi3, UCB1-GaSi10, UCB1-GaSi20 and UCB1-GaSi50. After calcination at 500 °C these materials exhibited decreasing surface areas and broadening pore distributions with increasing silicon content, indicating a loss of template effects. The position and dispersion of the gallium in UCB1-GaSi materials was investigated using 71Ga MAS-NMR, powder XRD, and STEM/EDS elemental mapping. The results indicate a high degree of gallium dispersion in all samples, with gallium oxide clusters or oligomers present at higher gallium content.
- Dombrowski, James P.,Johnson, Gregory R.,Bell, Alexis T.,Tilley, T. Don
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p. 11025 - 11034
(2016/07/15)
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- Hydrogenation of biomass-derived compounds containing a carbonyl group over a copper-based nanocatalyst: Insight into the origin and influence of surface oxygen vacancies
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New Mn-containing spinel-supported copper nanocatalysts were directly generated via a Cu-Mn-Al layered double hydroxide precursor route and employed in gas-phase hydrogenation of dimethyl succinate (DMS) to γ-butyrolactone (GBL). It was found that the introduction of manganese into catalyst precursors led to the formation of Mn-containing spinel phases, thereby giving rise to highly dispersive Cu0 nanoparticles and a large number of surface defects (i.e., oxygen vacancies (Ov), Mn2+ species) in reduced catalysts. As-formed copper-based nanocatalysts exhibited exceptional catalytic hydrogenation performance with stability enduring up to 100 h. Such high catalytic efficiency could reasonably be attributed to the surface synergism between Mn2+-Ov-Mn2+ defect structures and active metallic copper species, which controlled the key to hydrogenation related to the adsorption of DMS molecules and following activation of carbonyl groups and the dissociation of hydrogen. Most importantly, such copper-based nanocatalysts displayed great potential applications in the hydrogenations of other biomass-derived compounds containing carbonyl groups (e.g., acetol, levulinic acid, levulinic acid esters, and furfural). The present strategy enables us to tune the surface structures of catalysts for designing new type of copper-based catalysts with significantly enhanced catalytic performance.
- Hu, Qi,Yang, Lan,Fan, Guoli,Li, Feng
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p. 184 - 195
(2016/07/06)
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- Ru nanoparticles supported graphene oxide catalyst for hydrogenation of bio-based levulinic acid to cyclic ethers
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Ruthenium nanoparticles supported on graphene oxide (GO) catalysts have been evaluated for bio-based levulinic acid (LA) hydrogenation to produce vapor-phase cyclic ethers in a fixed-bed reactor. It was found that using the GO supported Ru nanoparticles (Ru/GO) produced additional hydrogenation products - cyclic ethers (54%) and γ-valerolactone (GVL; 41%), while Ru on carbon (Ru/C) catalysts gave only GVL with 100% LA conversion. To improve the yield of cyclic ethers, an additional two-step hydrogenation of LA via GVL was successfully carried out. This provided GVL as a second feedstock from which the Ru/GO catalyst could produce cyclic ethers such as methyltetrahydrofuran (MTHF) and tetrahydrofuran (THF). Ru on GO catalysts showed a 92% selectivity of predominantly cyclic ethers, including a 77% selectivity of MTHF through two steps process. Such a remarkable enhancement in activity and selectivity of LA hydrogenation over Ru/GO can be attributed to the well-dispersion of Ru nanoparticles, as well as favorable interaction with GO in the presence of oxy-functional groups of GO. In order to evaluate the active sites on the catalyst, they were characterized using different characterization techniques such as Raman, XRD, X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction (TPR), temperature-programmed desorption of NH3 (TPD), electron microscopy (TEM and SEM) and H2-chemisorption and N2 adsorption.
- Upare, Pravin P.,Lee, Maeum,Lee, Su-Kyung,Yoon, Ji Woong,Bae, Jongyoon,Hwang, Dong Won,Lee, U-Hwang,Chang, Jong-San,Hwang, Young Kyu
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p. 174 - 183
(2016/03/08)
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- PROCESS FOR CARRYING OUT A REACTION IN A REACTION COLUMN
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A process for carrying out a reaction in a reaction column, said process comprising: providing a first reactant to the reaction column in the liquid phase; contacting said first reactant with an excess of a second reactant such that reaction takes place within the reaction column to form a low boiling product and a high boiling product, at least a portion of said second reactant being provided to the reaction column in the vapour phase; recovering an overhead stream from at, or near, the top of the reaction column, said overhead stream comprising unreacted second reactant and the low boiling product; and recovering a bottoms stream from at, or near, the bottom of the reaction column comprising the high boiling product; wherein at least a portion of the heat required to vaporise the second reactant provided to the reaction column in the vapour phase is provided by heat exchange in a heat exchanger with a hot stream generated within the process other than a hot stream generated within the reaction column.
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Page/Page column 14-15
(2016/10/11)
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- Hydrogenation of succinic acid to tetrahydrofuran over ruthenium-carbon composite catalyst: Effect of catalyst preparation condition
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Ruthenium-carbon composite (Ru-C-X) catalysts were prepared by a single-step surfactanttemplating method at different sucrose/P123 molar ratio (X = 3, 5, 7, 9, 11, and 15). Ru-C-X (X = 3, 5, 7, 9, 11, and 15) catalysts were characterized by BET, nitrogen adsorption-desorption isotherm, XRD, and HR-TEM analyses. Liquid-phase hydrogenation of succinic acid to tetrahydrofuran (THF) was carried out over Ru-C-X catalysts in a batch reactor. The effect of sucrose/P123 molar ratio on the physicochemical properties and catalytic activities of Ru-C-X catalysts (X = 3, 5, 7, 9, 11, and 15) was investigated. It was revealed that Ru-C-X composite catalysts showed different ruthenium particle size depending on sucrose/P123 molar ratio. Characterization results showed that an optimal sucrose/P123 molar ratio was required to achieve fine dispersion of ruthenium in the Ru-C-X catalysts. Yield for THF in the hydrogenation of succinic acid increased with decreasing average ruthenium particle size of Ru-C-X catalysts. Ruthenium particle size served as an important factor determining the catalytic performance of Ru-C-X in the hydrogenation of succinic acid to THF. Among the catalysts tested, Ru-C-9 with the smallest ruthenium particle size showed the highest yield for THF.
- Hong, Ung Gi,Kang, Ki Hyuk,Song, Ji Hwan,Kim, Tae Hyeop,Song, In Kyu
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p. 10841 - 10845
(2016/10/18)
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- Hydrogenation of succinic acid to 1,4-butanediol over Re-Ru bimetallic catalysts supported on mesoporous carbon
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A series of Re-Ru bimetallic catalysts supported on mesoporous carbon (denoted as (0.6 - x)Re-xRu/MC) were prepared by a single-step surfactant-templating method and a subsequent incipient wetness impregnation method with a variation of ruthenium loading (x, mol%), and they were applied to the liquidphase hydrogenation of succinic acid to 1,4-butanediol (BDO). The effect of metal content on the catalytic activities and physicochemical properties of (0.6 - x)Re-xRu/MC catalysts was investigated. It was found that a Re-Ru miscible phase was formed in the catalysts during the reduction process, and it was responsible for strong interaction between rhenium and ruthenium. It was also revealed that reducibility, metal dispersion, and oxidation state of (0.6 - x)Re-xRu/MC catalysts were affected by Re:Ru molar ratio. In particular, the oxidation state was closely related to the hydrogen adsorption behavior of the catalysts. The amount of weak hydrogen-binding sites increased with increasing the ratios of metallic rhenium (Re0) and ruthenium (Ru0) with respect to total metallic species in the reduced (0.6 -x)Re-xRu/MC catalysts. Catalytic performance in the hydrogenation of succinic acid to BDO(0.6-x)Re-xRu/MC showed a volcano-shaped trend with respect to Re:Ru molar ratio. This result was well correlated with the amount of weak hydrogen-binding sites of the catalysts. Among the catalysts tested, 0.3Re-0.3Ru/MC with the largest amount of weak hydrogen-binding sites showed the best catalytic performance in the BDO production by hydrogenation of succinic acid.
- Kang, Ki Hyuk,Hong, Ung Gi,Bang, Yongju,Choi, Jung Ho,Kim, Jeong Kwon,Lee, Jong Kwon,Han, Seung Ju,Song, In Kyu
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p. 153 - 162
(2015/05/05)
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- Hydrogenation of succinic acid to 1,4-butanediol over Re-Ru bimetallic catalysts supported on mesoporous carbon
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A series of Re-Ru bimetallic catalysts supported on mesoporous carbon (denoted as (0.6-x)Re-xRu/MC) were prepared by a single-step surfactant-templating method and a subsequent incipient wetness impregnation method with a variation of ruthenium loading (x, mol%), and they were applied to the liquid-phase hydrogenation of succinic acid to 1,4-butanediol (BDO). The effect of metal content on the catalytic activities and physicochemical properties of (0.6-x)Re-xRu/MC catalysts was investigated. It was found that a Re-Ru miscible phase was formed in the catalysts during the reduction process, and it was responsible for strong interaction between rhenium and ruthenium. It was also revealed that reducibility, metal dispersion, and oxidation state of (0.6-x)Re-xRu/MC catalysts were affected by Re:Ru molar ratio. In particular, the oxidation state was closely related to the hydrogen adsorption behavior of the catalysts. The amount of weak hydrogen-binding sites increased with increasing the ratios of metallic rhenium (Re0) and ruthenium (Ru0) with respect to total metallic species in the reduced (0.6-x)Re-xRu/MC catalysts. Catalytic performance in the hydrogenation of succinic acid to BDO(0.6-x)Re-xRu/MC showed a volcano-shaped trend with respect to Re:Ru molar ratio. This result was well correlated with the amount of weak hydrogen-binding sites of the catalysts. Among the catalysts tested, 0.3Re-0.3Ru/MC with the largest amount of weak hydrogen-binding sites showed the best catalytic performance in the BDO production by hydrogenation of succinic acid.
- Kang, Ki Hyuk,Hong, Ung Gi,Bang, Yongju,Choi, Jung Ho,Kim, Jeong Kwon,Lee, Jong Kwon,Han, Seung Ju,Song, In Kyu
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p. 153 - 162
(2015/05/05)
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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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p. 2161 - 2178
(2015/11/24)
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- Tuning the catalytic selectivity in biomass-derived succinic acid hydrogenation on FeOx-modified Pd catalysts
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Succinic acid is an important biomass-derived C4 building block and is ready to be converted into various value-added chemicals. Here we report that tunable selectivity for the formation of 1,4-butanediol, γ-butyrolactone and tetrahydrofuran from aqueous succinic acid hydrogenation could be achieved on FeOx-promoted Pd/C catalysts. Fe was found to be an efficient promoter for the succinic acid hydrogenation, which not only improved the activity of the catalysts but also tuned the product distribution. Succinic acid could be transformed into 1,4-butanediol with a yield of over 70% in the presence of the Pd-5FeOx/C catalyst under the relatively mild conditions of 200°C and 5 MPa H2. The reaction pathway was also proposed according to the reaction and characterization results.
- Liu, Xiaoran,Wang, Xicheng,Xu, Guoqiang,Liu, Qiang,Mu, Xindong,Liu, Haichao
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supporting information
p. 23560 - 23569
(2015/11/28)
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