- One-Step catalytic transformation of carbohydrates and cellulosic biomass to 2,5-dimethyltetrahydrofuran for liquid Fuels
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Existing technologies to produce liquid fuels from biomass are typically energy-intensive, multistep processes. Many of these processes use edible biomass as starting material. Carbohydrates, such as monoand polysaccharides and cellulose, typically constitute 50-80% of plant biomass. Herein, we report that hexose from a wide range of biomass-derived carbohydrates, cellulose, and even raw lignocellulose (e.g., corn stover) can be converted into 2,5-dimethyltetrahydrofuran (DMTHF) in one step, in good yields and under mild conditions in water. Under the same conditions, 2-methyltetrahydrofuran is formed from pentose. The reaction employs a soluble rhodium catalyst, dihydrogen, and HI/HCl+NaI. The catalytic system is robust and can be recycled repeatedly without loss of activity. DMTHF is superior to ethanol and has many of the desirable properties currently found in typical petroleum-derived transportation fuels.
- Yang, Weiran,Sen, Ayusman
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- Effects of Water on the Copper-Catalyzed Conversion of Hydroxymethylfurfural in Tetrahydrofuran
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Reaction kinetics were studied to quantify the effects of water on the conversion of hydroxymethylfurfural (HMF) in THF over Cu/γ-Al2O3 at 448K using molecular H2 as the hydrogen source. We show that low concentrations of water (5wt %) in the THF solvent significantly alter reaction rates and selectivities for the formation of reaction products by hydrogenation and hydrogenolysis processes. In the absence of water, HMF was converted primarily to hydrogenolysis products 2-methyl-5-hydroxymethylfuran (MHMF) and 2,5-dimethylfuran (DMF), whereas reactions carried out in THF-H2O mixtures (THF/H2O=95:5 w/w) led to the selective production of the hydrogenation product 2,5-bis(hydroxymethyl)furan (BHMF) and inhibition of HMF hydrogenolysis.
- Liu, Yifei,Mellmer, Max A.,Alonso, David Martin,Dumesic, James A.
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- Selective hydrogenation of 5-ethoxymethylfurfural over alumina-supported heterogeneous catalysts
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We report here the synthesis and testing of a set of 48 alumina-supported catalysts for hydrogenation of 5-ethoxymethylfurfural. This catalytic reaction is very important in the context of converting biomass to biofuels. The catalysts are composed of one
- Ras, Erik-Jan,Maisuls, Sergio,Haesakkers, Paul,Gruter, Gert-Jan,Rothenberg, Gadi
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- Pd/C-catalyzed reactions of HMF: Decarbonylation, hydrogenation, and hydrogenolysis
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The diverse reactivity of 5-hydroxymethylfural (HMF) in Pd/C-catalyzed reactions is described with emphasis on the role of additives that affect selectivity. Three broad reactions are examined: decarbonylation, hydrogenation, and hydrogenolysis. Especially striking are the multiple roles of formic acid in hydrogenolysis/hydrogenation and in suppressing decarbonylation, as illustrated by the conversion of HMF to DMF. Hydrogenation of the furan ring is suppressed by CO2 and carboxylic acids. These results emphasize the utility of Pd/C as a convenient catalyst for upgradation of cellulosic biomass.
- Mitra, Joyee,Zhou, Xiaoyuan,Rauchfuss, Thomas
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- Heterogeneous Ketone Hydrodeoxygenation for the Production of Fuels and Feedstocks from Biomass
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In this work, we describe a simple, heterogeneous catalytic system for the hydrodeoxygenation (HDO) of 5-nonanone and 2,5-hexanedione, which we use as model compounds for more complex biomass-derived molecules. We present the stepwise reduction of ketones by using supported metal and solid acid catalysts to identify the intermediates en route to hydrocarbons. Although monoketone HDO can be achieved rapidly using moderate conditions (Ni/SiO2.Al2O3, HZSM-5, 200 °C, 1.38 MPa H2, 1 h), quantitative γ-polyketone HDO requires higher pressures and longer reaction times (Pd/Al2O3, HZSM-5, 2.76 MPa H2, 5 h), although these are more facile conditions than have been reported previously for γ-polyketone HDO. Stepwise HDO of the γ-polyketone shows the reaction pathway occurs through ring-closure to a saturated tetrahydrofuran species intermediate, which requires increased H2 pressure to ring-open and subsequently to fully HDO. This work allows for further understanding of bio-derived molecule defunctionalization mechanisms, and ultimately aids in the promotion of biomass as a feedstock for fuels and chemicals.
- Jenkins, Rhodri W.,Moore, Cameron M.,Semelsberger, Troy A.,Sutton, Andrew D.
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- Support Effect of Ru Catalysts for Efficient Conversion of Biomass-Derived 2,5-Hexanedione to Different Products
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Tuning the activity of supported metals by changing the properties of supports is a highly attractive strategy to realize some important reactions in biomass transformation. Herein, Ru nanoparticles supported on montmorillonite (MMT) and hydroxyapatite (HAP), denoted as Ru/MMT and Ru/HAP, were prepared. It was found that the activity of the Ru catalysts for different routes to convert biomass-derived 2,5-hexanedione (2,5-HD) could be controlled by the support materials. Ru/MMT was active for the synthesis of dimethyltetrahydrofuran from hydrogenation of 2,5-HD at 90 °C, while Ru/HAP showed excellent performance on the conversion of 2,5-HD into N-substituted tetrahydropyrroles at 30 °C via direct reductive amination. Systematic study revealed that the property of support materials influenced the activity of Ru/MMT and Ru/HAP for the different routes, affording different reaction pathways for conversion of 2,5-HD.
- Hua, Manli,Song, Jinliang,Huang, Xin,Hou, Minqiang,Fan, Honglei,Zhang, Zhaofu,Wu, Tianbin,Han, Buxing
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- Formic Acid-Assisted Selective Hydrogenolysis of 5-Hydroxymethylfurfural to 2,5-Dimethylfuran over Bifunctional Pd Nanoparticles Supported on N-Doped Mesoporous Carbon
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Biomass-derived 5-hydroxymethylfurfural (HMF) is regarded as one of the most promising platform chemicals to produce 2,5-dimethylfuran (DMF) as a potential liquid transportation fuel. Pd nanoparticles supported on N-containing and N-free mesoporous carbon materials were prepared, characterized, and applied in the hydrogenolysis of HMF to DMF under mild reaction conditions. Quantitative conversion of HMF to DMF was achieved in the presence of formic acid (FA) and H2 over Pd/NMC within 2 h. The reaction mechanism, especially the multiple roles of FA, was explored through a detailed comparative study by varying hydrogen source, additive, and substrate as well as by applying in situ ATR-IR spectroscopy. The major role of FA is to shift the dominant reaction pathway from the hydrogenation of the aldehyde group to the hydrogenolysis of the hydroxymethyl group via the protonation by FA at the C-OH group, lowering the activation barrier of the C?O bond cleavage and thus significantly enhancing the reaction rate. XPS results and DFT calculations revealed that Pd2+ species interacting with pyridine-like N atoms significantly enhance the selective hydrogenolysis of the C?OH bond in the presence of FA due to their high ability for the activation of FA and the stabilization of H?.
- Hu, Bin,Warczinski, Lisa,Li, Xiaoyu,Lu, Mohong,Bitzer, Johannes,Heidelmann, Markus,Eckhard, Till,Fu, Qi,Schulwitz, Jonas,Merko, Mariia,Li, Mingshi,Kleist, Wolfgang,H?ttig, Christof,Muhler, Martin,Peng, Baoxiang
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- ORGANOTINS AS ETHERIFICATION CATALYSTS. II. CATALYTIC CONVERSION OF ALCOHOLS TO OPEN-CHAIN AND CYCLIC ETHERS BY ORGANOTIN TRICHLORIDES
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1,5-Heptadien-4-ol and various 1,4- and 1,5-glycols are catalytically converted to open-chain and cyclic ethers respectively in the presence of butyltin trichloride.The dehydration of alcohols is mediated by formation of organoalkoxytin dihalides BuSn(OR)Cl2.A mechanism for the formation of these ethers is proposed.The catalytic activity of ether organotins together with SnCl4 has been examined for the conversion of 1,5-pentanediol to THP; the scale of the catalytic efficiency is: MeSnCl3 >= PhSnCl3 > SnCl4 > BuSnCl3 > Me2SnCl2 > Bu2SnCl2 >> (Bu2SnCl)2O.
- Tagliavini, Giuseppe,Marton, Daniele,Furlani, Donatella
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- Mechanistic study of a one-step catalytic conversion of fructose to 2,5-dimethyltetrahydrofuran
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Carbohydrates, such as fructose, can be fully dehydroxylated to 2,5-dimethyltetrahydrofuran (DMTHF), a valuable chemical and potential gasoline substitute, by the use of a dual catalytic system consisting of HI and RhX 3 (X=Cl, I). A mechanistic study has been carried out to understand the roles that both acid and metal play in the reaction. HI serves a two-fold purpose: HI acts as a dehydration agent (loss of 3 H2O) in the initial step of the reaction, and as a reducing agent for the conjugated carbinol group in a subsequent step. I2 is formed in the reduction step and metal-catalyzed hydrogenation reforms HI. The rhodium catalyst, in addition to catalyzing the reaction of iodine with hydrogen, functions as a hydrogenation catalyst for C=O and C=C bonds. A general mechanistic scheme for the overall reaction is proposed based on identification of intermediates, independent reactions of the intermediates, and deuterium labeling studies. Copyright
- Grochowski, Matthew R.,Yang, Weiran,Sen, Ayusman
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- Zinc-assisted hydrodeoxygenation of biomass-derived 5-hydroxymethylfurfural to 2,5-Dimethylfuran
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2,5-Dimethylfuran (DMF), a promising cellulosic biofuel candidate from biomass derived intermediates, has received significant attention because of its low oxygen content, high energy density, and high octane value. A bimetallic catalyst combination containing a Lewis-acidic ZnII and Pd/C components is effective for 5-hydroxymethylfurfural (HMF) hydrodeoxygenation (HDO) to DMF with high conversion (99%) and selectivity (85% DMF). Control experiments for evaluating the roles of zinc and palladium revealed that ZnCl2 alone did not catalyze the reaction, whereas Pd/C produced 60% less DMF than the combination of both metals. The presence of Lewis acidic component (Zn) was also found to be beneficial for HMF HDO with Ru/C catalyst, but the synergistic effect between the two metal components is more pronounced for the Pd/Zn system than the Ru/Zn. A comparative analysis of the Pd/Zn/C catalyst to previously reported catalytic systems show that the Pd/Zn system containing at least four times less precious metal than the reported catalysts gives comparable or better DMF yields. The catalyst shows excellent recyclability up to 4 cycles, followed by a deactivation, which could be due to coke formation on the catalyst surface. The effectiveness of this combined bimetallic catalyst has also been tested for one-pot conversion of fructose to DMF.
- Saha, Basudeb,Bohn, Christine M.,Abu-Omar, Mahdi M.
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- Highly efficient synchronized production of phenol and 2,5-dimethylfuran through a bimetallic Ni-Cu catalyzed dehydrogenation-hydrogenation coupling process without any external hydrogen and oxygen supply
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2,5-Dimethylfuran (DMF) and phenol are considered as one of the new-fashioned liquid transportation biofuels and a key motif for industrial chemicals, respectively. Herein, a highly efficient vapor-phase dehydrogenation-hydrogenation coupling process over bimetallic Ni-Cu alloy nanocatalysts was established for the synchronized production of phenol and DMF with unprecedentedly high yields (>97%) from two cyclohexanol (CHL) and biomass-derived 5-hydroxymethylfurfural (HMF) substrates, without any external hydrogen and oxygen supply. Systematic characterization and catalytic experiments revealed that the production of phenol went through a consecutive triple-dehydrogenation process from CHL, while HMF was simultaneously hydrogenated into DMF using active hydrogen species generated from the dehydrogenation process. The bimetallic Ni-Cu alloy nanostructures derived from Ni-Cu-Al layered double hydroxide precursors and strong metal-support interactions play important roles in governing the present coupling process. An appropriate Ni-Cu alloy nanostructure could greatly facilitate the dehydrogenative aromatization of CHL, thus significantly improving the selectivities to both phenol and DMF. Such an unparalleled efficient, eco-friendly and versatile coupling process for the synchronized production of various substituted phenols and DMF makes it practically promising for large-scale industrial applications in terms of green chemistry and sustainable development.
- Li, Wei,Fan, Guoli,Yang, Lan,Li, Feng
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- Molybdenum Oxide-Modified Iridium Catalysts for Selective Production of Renewable Oils for Jet and Diesel Fuels and Lubricants
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Supported inverse metal-metal oxide catalysts have received significant research interest owing to their effective hydrodeoxygenation (HDO) activity toward biomass substrates, but the high cost of the reported catalysts poses a challenge for commercialization. We present the synthesis of a series of metal-metal oxide catalysts, Ir-MOx/SiO2 (M = Re, Mo, W, V, or Nb) and M′-MoOx/SiO2 (M = Rh, Ru, Pt, or Pd) and their HDO performance on multifuran (high carbon) substrates to produce renewable jet and diesel fuels and lubricant base oils. A MoOx-modified Ir/SiO2 catalyst with a Mo/Ir ratio of 0.13 (Ir-MoOx/SiO2) exhibits the highest product yield (78-96%) under mild reaction conditions. Controlled experiments using probe substrates reveal that furan ring hydrogenation and C-O hydrogenolysis of saturated and unsaturated furan rings occur in a sequential manner. The carbon atom adjacent to the furan or saturated furan ring of substrates or intermediate compounds undergoes slow C-C bond scission, resulting in a small fraction of lighter alkanes. Catalyst characterization suggests that Ir is reduced to a fully metallic state to dissociate hydrogen for hydrogenation. Intact MoOx, partly covering the Ir metal surface, promotes ring opening, hydrogenolysis of etheric and alcoholic C-O bonds, and hydrogenation of Ca? O bonds. This study highlights the potential of low-cost metal-metal oxide catalysts with low loading of oxophilic metals to enable cost-competitive production of bioproducts and demonstrates applicability of these catalysts on other substrates, including fatty acids, fatty esters, and lipids.
- Liu, Sibao,Zheng, Weiqing,Fu, Jiayi,Alexopoulos, Konstantinos,Saha, Basudeb,Vlachos, Dionisios G.
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- Tailored one-pot production of furan-based fuels from fructose in an ionic liquid biphasic solvent system
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The one-pot catalytic transformation of biomass to useful products is desirable for saving cost and time. The integration of the various reaction steps need to address the presence of incompatible reaction conditions and numerous side reactions. We report a novel process for the one-pot production of furan-based fuels, 2,5-dimethylfuran (DMF) and 2,5-dihmethyltetrahydrofuran (DMTF), from fructose by optimizing the synergic effect of an ionic liquid promoted Ru/C catalyst and the solvent effect. The dehydration of fructose and subsequent in situ hydrodeoxygenation of HMF to DMF and DMTF on Ru/C were enhanced by the use of an ionic liquid and a biphasic [BMIm]Cl/THF solvent. Elemental analysis, X-ray Photoelectron Spectroscopy, Raman spectroscopy and H2-temperature programmed reduction-mass spectroscopy characterization showed that the ionic liquid modified the electronic density of the Ru species to favor HMF in situ hydrodeoxygenation. Moreover, THF served as a reaction-extraction solvent that extracted DMF and DMTF from the reaction layer to avoid further side reactions. A rational design that gave enhancement of the catalytic performance and product protection provides a promising strategy for the one-pot conversion of biomass to desired fuels.
- Li, Changzhi,Cai, Haile,Zhang, Bo,Li, Weizhen,Pei, Guangxian,Dai, Tao,Wang, Aiqin,Zhang, Tao
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- Catalytic conversion of sorbitol to gasoline-ranged products without external hydrogen over Pt-modified Ir-ReOx/SiO2
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Deoxygenation of sorbitol was carried out over a Pt-modified Ir-ReOx/SiO2 catalyst in biphasic solvent system (n-decane + H2O) without external hydrogen. Good yield of gasoline-ranged products was obtained including C5-C6 alkanes and C2-C6 mono-functionalized compounds such as ketones, alcohols, cyclic ethers and carboxylic acids. The Pt(3 wt%)-Ir-ReOx/SiO2 catalyst showed the best performance in the production of gasoline-ranged products. The maximum yield of gasoline-ranged products was 42%. The distribution of the products can be tuned by the addition of HZSM-5. The main products were C5-C6 alkanes with addition of HZSM-5 while the main products were C2-C6 mono-functionalized compounds without addition of HZSM-5. Characterizations such as TPR, XRD, TEM, XANES, EXAFS, CO adsorption were performed. The results demonstrated that the Pt-Ir-ReOx/SiO2 catalyst showed the structure of Pt-Ir alloy particles partially covered with ReOx species. The number of surface Pt atoms in Pt(3)-Ir-ReOx/SiO2 was larger than that of Pt/SiO2 or Pt-ReOx/SiO2 because of the small size of Pt-Ir alloy particles. The large number of surface Pt atoms and the synergetic effect of Pt, Ir and ReOx species make the catalyst efficiently generate hydrogen by aqueous phase reforming of sorbitol, and the generated hydrogen is consumed in the hydrogenolysis C-O bonds.
- Liu, Sibao,Okuyama, Yasuyo,Tamura, Masazumi,Nakagawa, Yoshinao,Imai, Akio,Tomishige, Keiichi
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- Ruthenium-8-quinolinethiolate-phenylterpyridine versus ruthenium-bipyridine-phenyl-terpyridine complexes as homogeneous water and high temperature stable hydrogenation catalysts for biomass-derived substrates
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[(4′-Ph-terpy)(bipy)Ru(L)](OTf)n and [(4′-Ph-terpy)(quS)Ru(L)](OTf)n (n = 0 or 1 depending on the charge of L, L = labile ligand, e.g., H2O, CH3CN or OTf, bipy = 2,2′-bipyridine, quS = quinoline-8-thiolate) have been evaluated as catalysts for the hydrogenation of the biomass-derivable C6-substrates 2,5-dimethylfuran (obtainable from 5-hydroxymethylfurfural) and 2,5-hexanedione (the hydrolysis product of 2,5-dimethylfuran). Operating in aqueous acidic medium at T = 175-225 °C the bipy complex is only marginally active, while the quinoline-8-thiolate complex realizes yields of hydrogenated products up to 97% starting from 2,5-hexanedione and up to 66% starting from 2,5-dimethylfuran. The catalyst can also convert the 5-HMF derived acetone 4-(5-methyl-2-furanyl)-3-buten-2-one into 2,5,8-nonatriol, a potentially valuable cross-linker for polymer formulations. On the basis of DFT calculations, the higher activity of the quinoline-8-thiolate complex is proposed to be rooted in a metal-ligand bifunctional mechanism for the heterolytic activation and transfer of dihydrogen to the carbonyl substrate with the hydride-thiol complex [(4′-Ph-terpy)(quSH)Ru(H)]+ as the active catalyst.
- Sullivan, Ryan J.,Kim, Jin,Hoyt, Caroline,Silks, Louis A.,Schlaf, Marcel
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- Ni Nanoparticles Inlaid Nickel Phyllosilicate as a Metal-Acid Bifunctional Catalyst for Low-Temperature Hydrogenolysis Reactions
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Hydrogenolysis of carbon-oxygen bonds is a versatile synthetic method, of which hydrogenolysis of bioderived 5-hydroxymethylfurfural (HMF) to furanic fuels is especially attractive. However, low-temperature hydrogenolysis (in particular over non-noble catalysts) is challenging. Herein, nickel nanoparticles (NPs) inlaid nickel phyllosilicate (NiSi-PS) are presented for efficient hydrogenolysis of HMF to yield furanic fuels at 130-150 °C, being much superior with impregnated Ni/SiO2 catalysts prepared from the same starting materials. NiSi-PS also shows a 2-fold HMF conversion intrinsic rate and 3-fold hydrogenolysis rate compared with the impregnated Ni/SiO2. The superior performance originated from the synergy of highly dispersed nickel NPs and substantially formed acid sites due to coordinatively unsaturated Ni (II) sites located at the remnant nickel phyllosilicate structure, as revealed by detailed characterizations. The model reactions over the other reference catalysts further highlighted the metal-acid synergy for hydrogenolysis reactions. NiSi-PS can also efficiently catalyze low-temperature hydrogenolysis of bioderived furfural and 5-methylfurfural, demonstrating a great potential for other hydrogenolysis reactions.
- Kong, Xiao,Zhu, Yifeng,Zheng, Hongyan,Li, Xianqing,Zhu, Yulei,Li, Yong-Wang
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- A Convenient One-step Preparation of Oxacyclanes by Dehydration of Diols over Alumina
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Dehydration of 1,4-, 1,5-, or 1,6- alkanediols over alumina at 220-250 deg C in a distillation apparatus gave the corresponding 5- to 7-membered oxacyclanes in good yield of 51-71percent.Diethylene glycol also gave 1,4-dioxane in 49percent yield, whereas attempted one-step synthesis of crown ethers from polyethylene glycols in a similar manner resulted in the predominant formation of 1,4-dioxane without any trace of crown ether.
- Inoue, Yoshihisa,Deguchi, Shokichiro,Hakushi, Tadao
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- Hydrogenation of 5-hydroxymethylfurfural in supercritical carbon dioxide-water: A tunable approach to dimethylfuran selectivity
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The use of supercritical carbon dioxide-water on the hydrogenation of 5-hydroxymethylfurfural (HMF) was investigated over a Pd/C catalyst. It was possible to achieve a very high yield (100%) of DMF within the reaction time of 2 hours at 80 °C. A significant effect of CO2 pressure was observed on the product distribution. Simply by tuning the CO2 pressure it was possible to achieve various key compound, such as tetrahydro-5-methyl-2-furanmethanol (MTHFM) (10 MPa) with very high selectivity. Optimization of other reaction parameters revealed that H 2 pressure, temperature, as well as the CO2-water mole ratio, played an important role in the selectivity to the targeted DMF. It is interesting to note that a very high yield of DMF was achieved when a combination of CO2 and water was used. For instance, in the absence of water or CO2, the selectivity of DMF was low; similarly, an excess of water against the fixed pressure of CO2 reduced the selectivity to DMF. Hence, an optimized amount of water was mandatory in the presence of CO2 for the formation of DMF with high selectivity. This method was successfully extended to the hydrogenation of furfural, which could afford 100% selectivity to 2-methylfuran with complete conversion within a very short reaction time of 10 min. The studied catalyst could be recycled successfully without significant loss of catalytic activity.
- Chatterjee, Maya,Ishizaka, Takayuki,Kawanami, Hajime
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- Direct use of humic acid mixtures to construct efficient Zr-containing catalysts for Meerwein-Ponndorf-Verley reactions
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With the increasing demands for energy and carbon resources, exploration of novel utilization approaches of fossil resources and promotion of the conversion of sustainable resources become critical issues facing human society. In this study, we used humic acids (HAs), which are important derivatives from the low-rank coal, and the transition metal zirconium (Zr) to construct novel Zr-containing catalysts (Zr-HAs) for Meerwein-Ponndorf-Verley (MPV) reactions of biomass-derived platforms. Both commercial HAs and HAs extracted directly from lignite without any purification were used as raw materials to prepare the catalysts. The results showed that Zr-HAs catalysts were highly efficient for the conversion of furfural, with a high furfuryl alcohol yield of up to 97%, and also effective for the conversion of other carbonyl compounds with different structures under mild conditions. This novel strategy to construct catalysts using HAs as raw materials may be beneficial for both value-added utilization of low-rank coal and the conversion of biomass resources.
- Sha, Yufei,Xiao, Zhenhuan,Zhou, Huacong,Yang, Keli,Song, Yinmin,Li, Na,He, Runxia,Zhi, Keduan,Liu, Quansheng
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- Efficient production of the liquid fuel 2,5-dimethylfuran from fructose using formic acid as a reagent
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Three in one: New reagents are needed to generate liquid fuels from biomass, but the reagents must serve multiple roles. For the conversion of fructose into the title compound 1, formic acid serves three roles: assists in the isomerization/dehydration, serves as an H2 source for hydrogenation, and helps deoxygenate the alcohol functional groups.
- Thananatthanachon, Todsapon,Rauchfuss, Thomas B.
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- Self-tuned properties of CuZnO catalysts for hydroxymethylfurfural hydrodeoxygenation towards dimethylfuran production
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5-Hydroxymethylfurfural (HMF) is a very valuable platform molecule obtained from biomass. It can be catalytically transformed to many industrially relevant products of both oxidation and reduction reactions. In this work, we showed that robust CuZnO can be an efficient, self-tuned catalyst for 2,5-dimethylfuran (DMF) (biofuel additive) synthesis. We showed that CuZnO catalysts can be further activated in the reaction environment and this process depends strongly on the initial catalyst properties and therefore on the catalyst preparation method. Smaller copper particles are more active but more prone to carbon deposit formation. Based on activity tests and extensive characterization, we have concluded that both Cun+ and Cu0 sites are necessary for high HMF conversion. While these two sites favor high conversion and high 2,5-bishydroxymethylfuran (BHMF) yield, the in situ formation of Lewis acid sites is proposed to be necessary for achieving a high DMF yield.
- Brzezińska, Magdalena,Keller, Nicolas,Ruppert, Agnieszka M.
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- Hydrogenation of 2,5-dimethylfuran on hexagonal-boron nitride- and silica-supported platinum catalysts
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Hydrogenation of furanic compounds is one of the important reactions for upgrading of bio-oils and production of diesel fuels. Platinum catalysts supported on amorphous silica and hexagonal boron nitride (h-BN) were prepared by incipient wetness impregnation and subsequent reduction, and were used for the vapor-phase hydrogenation of 2,5-dimethylfuran in hydrogen at atmospheric pressure and a temperature range of 150–350 °C. For the same amount of Pt loading (1 wt%), the particle size of Pt supported on h-BN was larger than that on silica, resulting in a lower amount of CO chemisorption for Pt/BN than that for Pt/SiO2. Using the same amount of active sites, Pt/BN exhibited a 3-fold higher turnover frequency than Pt/SiO2 for the hydrogenation of 2,5-dimethylfuran whereas both catalysts gave similar product distributions with high selectivity to 2-hexanone at any conversion and low selectivity to n-hexane at high conversion. Contact time studies of 2,5-dimethylfuran hydrogenation on Pt/BN suggested that 2,5-dimethylfuran formed the ring-opening product, 2-hexanone and the ring-saturation product, 2,5-dimethyltetrahydrofuran in parallel, with the rate of the direct furan ring-opening being 9-fold higher than that of the furan ring-saturation.
- Goto, Hiroshi,Takagaki, Atsushi,Kikuchi, Ryuji,Oyama, S. Ted
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- Hydroconversion of 5-Hydroxymethylfurfural to 2,5-Dimethylfuran and 2,5-Dimethyltetrahydrofuran over Non-promoted Ni/SBA-15
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The selective hydroconversion of 5-hydroxymethylfurfural (HMF) to biofuels is currently highly sought-for. While the literature has demonstrated that this reaction is possible on promoted Ni catalysts, we show here that a monometallic, non-promoted Ni/SBA-15 catalyst, prepared by incipient wetness impregnation, can convert HMF to 2,5-dimethylfuran (DMF) and to 2,5-dimethyltetrahydrofuran (DMTHF) at 180 °C, in a consecutive way. Through a control over reaction time, high yields to DMF (71 %, at conversion of 93 %) or DMTHF (97 %, at conversion of 100 %) can be achieved. Kinetic modelling suggests a preferential route to DMF via 5-methylfurfural (MFFR) as intermediate, though the route via 2,5-bis(hydroxylmethyl)furan (BHMF) is also present. The favored route in the experimental conditions involves the hydrogenolysis of the hydroxyl group of HMF as first step, followed by the hydrogenation of the aldehyde function, to methylfurfuryl alcohol (MFOL). It is suggested a higher reaction rate of hydrogenation or hydrogenolysis of the side group is linked to the presence of a methyl group in the molecule. No hydrogenation of the furan ring is detected on the intermediates.
- Chen, Shuo,Ciotonea, Carmen,De Oliveira Vigier, Karine,Jér?me, Fran?ois,Wojcieszak, Robert,Dumeignil, Franck,Marceau, Eric,Royer, Sebastien
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- Efficient hydrogenolysis of 5-hydroxymethylfurfural to 2,5-dimethylfuran over a cobalt and copper bimetallic catalyst on N-graphene-modified Al2O3
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2,5-Dimethylfuran (DMF) is an important candidate for liquid fuels and can be produced from biomass derived 5-hydroxymethylfurfural (HMF). Efficient transformation of HMF to DMF has not been achieved over a non-noble catalyst under milder conditions. Herein, we developed a copper and cobalt bimetallic nanoparticle catalyst supported on N-graphene-modified Al2O3 (CuCo/NGr/α-Al2O3). It was found that CuCo/NGr/α-Al2O3 could catalyze the conversion of HMF to DMF effectively and the yield of DMF could reach 99%. The catalyst was completely not active for the hydrogenation of the C=C bond in furan and thus no 2,5-bis(hydroxymethyl)tetrahydrofuran (DHTHF) and 2,5-dimethyltetrahydrofuran (DMTHF) were detected.
- Guo, Weiwei,Liu, Hangyu,Zhang, Suqi,Han, Hongling,Liu, Huizhen,Jiang, Tao,Han, Buxing,Wu, Tianbin
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- Direct one-pot conversion of monosaccharides into high-yield 2,5-dimethylfuran over a multifunctional Pd/Zr-based metal-organic framework@sulfonated graphene oxide catalyst
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A one-pot conversion of monosaccharides (fructose and glucose) into high-yield 2,5-dimethylfuran (2,5-DMF) is demonstrated over a multifunctional catalyst obtained by loading Pd on a Zr-based metal-organic framework (UiO-66) that is deposited on sulfonated graphene oxide (Pd/UiO-66@SGO). The Br?nsted acidity associated with UiO-66@SGO activates the fructose dehydration to form 5-hydroxymethylfurfural (5-HMF), while the Pd nanoparticles further convert 5-HMF to 2,5-DMF by hydrogenolysis and hydrogenation. The results show that under the optimized reaction conditions of 160 °C and 1 MPa H2 in tetrahydrofuran for 3 h, the yield of 2,5-DMF is as high as 70.5 mol%. This value is higher than the previously reported values, and the direct conversion of fructose can be achieved without additional purification of 5-HMF from the reaction mixture. In addition, for the first time, glucose is converted to 2,5-DMF with a high yield of 45.3 mol%. A recyclability test suggests that the 4.8 wt% Pd loaded on the UiO-66@SGO catalyst can be re-used up to five times.
- Insyani, Rizki,Verma, Deepak,Kim, Seung Min,Kim, Jaehoon
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- Deuterium-Labeling Study of the Hydrogenation of 2-Methylfuran and 2,5-Dimethylfuran over Carbon-Supported Noble Metal Catalysts
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2-Methylfuran and 2,5-dimethylfuran were deuterated over Pd and Pt catalysts at 90-220°C. Furan ring saturation over a Pd/C catalyst occurred at low reaction temperatures, which led to deuterated THFs, followed by progressive D exchange in the THF ring at higher temperatures. Finally, H/D exchange occurred in the methyl groups on the THF ring. Cleavage of the CO bond also occurred over a Pd/C catalyst at elevated temperatures, which resulted in deuterated ketones, for which all H atoms were exchanged for D. Alcohols were produced over a Pt/C catalyst at low temperatures because they are more stable than the corresponding ketones. D replaced H on all carbon atoms of the furan ring and saturated the O and C atoms of the broken CO bond in both deuterated 2-pentanol and 2-hexanol. At low temperatures (90-105°C), all H atoms in the deuterated alcohols were exchanged for D except for the last two hydrogen atoms on the methyl groups.
- Kang, Jungshik,Vonderheide, Anne,Guliants, Vadim V.
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- A Pd-Catalyzed in situ domino process for mild and quantitative production of 2,5-dimethylfuran directly from carbohydrates
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An in situ domino process has been developed to be highly efficient for direct and mild conversion of various hexose sugars to the biofuel 2,5-dimethylfuran in almost quantitative yields, without separation of unstable intermediates at 120 °C in n-butanol, by using polymethylhydrosiloxane and hydrophobic Pd/C as a H-donor and a bifunctional catalyst, respectively. Among the cascade reactions, the hydrosilylation process was confirmed by deuterium-labeling and kinetic studies to be favorable for sugar dehydration and exclusively acts on deoxygenation of in situ formed intermediates including furanic alcohols and aldehydes to DMF via a hydride transfer process that was facilitated by an alcoholic solvent. The catalytic system is more selective than the H2- participated counterpart, and could be scaled up with only 0.04 mol% catalyst loading, giving DMF in a comparable yield of 85%. Moreover, Pd(0) was demonstrated to be the active species for deoxygenation, and the heterogeneous catalyst exhibited good recyclability with little elemental leaching.
- Li, Hu,Zhao, Wenfeng,Riisager, Anders,Saravanamurugan, Shunmugavel,Wang, Zhongwei,Fang, Zhen,Yang, Song
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- Oxidation of lower alkenes by Α-oxygen (FeIII–O??)Α on the FeZSM-5 surface: The epoxidation or the allylic oxidation?
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Reactions of anion-radical α-oxygen (FeIII–O??)α with propylene and 1-butene on sodium-modified FeZSM-5 zeolites were studied in the temperature range from ?60 to 25 °C. Products were extracted from the zeolite surface and identified. It was found that main reaction pathway was the epoxides formation. Selectivity for epoxides at ?60 °C was 59–64%. Other products were formed as a result of secondary transformations of epoxides on the zeolite surface. According to IR spectroscopy, the oxidation of propylene over the entire temperature range and 1-butene at ?60 °C were not accompanied by the formation of (FeIII–OH)α groups, in distinction to methane oxidation. This testifies that hydrogen abstraction does not occur. In case of 1-butene reaction with α-oxygen at 25 °C, hydrogen abstraction occurred but was insignificant, ca 7%. According to DFT calculation ferraoxetane intermediate formation is preferable over hydrogen abstraction. Following decomposition of this intermediate leads to the propylene oxide (PO) formation. The results may be relevant to the low selectivity problem of the silver catalyst in propylene epoxidation and raise doubts about the presently accepted mechanism explaining an adverse effect of allylic hydrogen.
- Starokon, Eugeny V.,Malykhin, Sergei E.,Parfenov, Mikhail V.,Zhidomirov, Georgy M.,Kharitonov, Alexander S.
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- Selective hydrodeoxygenation of 5-hydroxymethylfurfural to 2,5-dimethylfuran on Ru-MoOx/C catalysts
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Selective hydrogenation of 5-hydroxymethylfurfural (HMF) has potential application in high quality biofuels. Herein, the catalytic hydrodeoxygenation (HDO) of HMF to 2,5-dimethylfuran (DMF) was investigated using bi-functional Ru-MoOx/C catalyst prepared by initial wetness impregnation. The high dispersion and electronic transfer between Ru and MoOx were demonstrated by a series of characterization techniques. During this HDO process, the synergy effect between metallic Ru and acidic MoOx species in the Ru-MoOx/C catalyst plays an essential role in obtaining maximized target product DMF (79.4%) via effective aldehyde group hydrogenation by Ru followed by dehydration over MoOx. This work also elucidated that DMF production proceeded through two distinct pathways: the 2,5-hydroxymethyl furan intermediate was preferable by the aldehyde group hydrogenation of HMF over the Ru-MoOx/C catalyst. Over MoOx/C catalyst, comparatively, 5-methyl furfural was the key intermediate by direct hydrogenolysis of the hydroxyl group in HMF. This kind of catalyst is stable for the first two runs by maintaining the target product yield. After the third run, the catalyst showed deactivation gradually but could be almost completely recovered after regeneration by H2 reduction.
- Yang, Yue,Liu, Qiying,Li, Dan,Tan, Jin,Zhang, Qi,Wang, Chenguang,Ma, Longlong
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- Insights into the Ring-Opening of Biomass-Derived Furanics over Carbon-Supported Ruthenium
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The selective ring-opening of cellulose-derived furanic molecules is a promising pathway for the production of industrially relevant linear oxygenates, such as 1,6-hexanediol. 2,5-Dimethylfuran (DMF) is employed as a model compound in a combined experimental and computational investigation to provide insights into the metal-catalyzed ring-opening. Ring-opening to 2-hexanol and 2-hexanone and ring-saturation to 2,5-dimethyltetrahydrofuran (DMTHF) are identified as two main parallel pathways. DFT calculations and microkinetic modeling indicate that DMF adsorbs on Ru in an open-ring configuration, which is potentially a common surface intermediate that leads to both ring-opening and ring-saturation products. Although the activation barriers for the two pathways are comparable, the formation of DMTHF is more thermodynamically favorable. In addition, steric interactions with co-adsorbed 2-propoxyl, derived from the solvent, and the oxophilic nature of Ru play key roles to determine the product distribution: the former favors less bulky, that is, ring-closed, intermediates, and the latter retards O?H bond formation. Finally, we show that the hydrodeoxygenation of oxygenated furanics, such as 5-methylfurfural and (5-methyl-2-furyl)methanol, on Ru occurs preferentially at oxygen-containing side groups to form DMF, followed by either ring-opening or ring-saturation.
- Gilkey, Matthew J.,Mironenko, Alexander V.,Yang, Leerang,Vlachos, Dionisios G.,Xu, Bingjun
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- Cooperative catalysis of Pt/C and acid resin for the production of 2,5-dimethyltetrahydrofuran from biomass derived 2,5-hexanedione under mild conditions
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Conversion of biomass into 2,5-dimethyltetrahydrofuran (DMTHF), an excellent fuel additive, solvent, and industrial intermediate, is an important reaction in green chemistry. In this work, different combinations of supported metal catalysts and solid acids were investigated for the synthesis of DMTHF from biomass derived diketone (2,5-hexanedione, 2,5-HD). The results showed that commercial Pt/C and solid acid AmberliteIR-120H had an excellent cooperative effect on the reaction. 2,5-HD could be converted into DMTHF with a yield up to 99% under milder conditions. Further experiments indicated that 2,5-hexanediol (2,5-HDO) is a key intermediate in the reaction. The catalyst system could be facilely recovered due to the heterogeneity and reused several times without notable change in the performance.
- Zhou, Huacong,Song, Jinliang,Meng, Qinglei,He, Zhenhong,Jiang, Zhiwei,Zhou, Baowen,Liu, Huizhen,Han, Buxing
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- STEREOCHEMISTRY OF THE IODOCYCLIZATION OF UNSATURATED ALCOHOLS
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The corresponding tetrahydrofuran derivatives were obtained by iodination of δ,ε-unsaturated alcohols containing substituents attached to the α-carbon atom.The effect of substituents on the stereochemistry of the products and the rate of iodination of the
- Gevaza, Yu. I.,Kupchik, I. P.,Staninets, V. I.
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- Towards sustainable hydrogenation of 5-(hydroxymethyl)furfural: A two-stage continuous process in aqueous media over RANEY catalysts
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The hydrogenation of 5-(hydroxymethyl)furfural (HMF) to 2,5-bis(hydroxymethyl)tetrahydrofuran (DHMTHF) in aqueous media under relatively mild reaction conditions has been investigated over heterogeneous RANEY Cu and Ni catalysts using a continuous-flow hydrogenation reactor. These RANEY catalysts were selected following a screening of several catalysts including precious metals supported on carbon for the hydrogenation of HMF. A single-stage versus a two-stage process for the hydrogenation of HMF into DHMTHF, i.e. via 2,5-dihydroxymethylfuran (DHMF) has been evaluated. The best result with an average selectivity of 98% for DHMTHF was obtained using a two-stage process; RANEY Cu was used as a catalyst for the highly selective hydrogenation of HMF to DHMF (92 mol%) in the first stage and this product was used without further purification for in a second-stage selective hydrogenation of DHMF into DHMTHF using RANEY Ni as a catalyst. The influence of the HMF concentration in the feeding solution (1-3 wt%), flow rate (0.05-0.25 mL min-1) and total pressure (20-90 bar) were investigated for the first-stage hydrogenation of HMF into DHMF over RANEY Cu. HMF was found to exert an inhibiting effect on the conversion due to strong adsorption. The RANEY Ni catalyst used in the second stage gradually deactivated. A procedure for in situ regeneration of the partially deactivated RANEY Ni catalyst using acetic acid washing was investigated with limited success.
- Lima, Sérgio,Chadwick, David,Hellgardt, Klaus
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- Ring closure reactions of substituted 4-pentenyl-1-oxy radicals. The stereoselective synthesis of functionalized disubstituted tetrahydrofurans
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N-(Alkyloxy)pyridine-2(1H)-thiones 3 and benzenesulfenic acid O-esters 5 have been synthesized from substituted 4-pentenols 1 or the derived tosylates. Compounds 3 and 5 are efficient sources of free alkoxy radicals 6 which undergo synthetically useful fast ring closure reactions 6 → 8 [k(exo) = (2 ± 1) x 108 s-1 to (6 ± 2) x 109 s-1 (T = 30 ± 0.2°C)]. Tetrahydrofurfuryl radicals 8 can be trapped with, e.g., hydrogen or chlorine atom donors to afford either trans- or cis-disubstituted tetrahydrofurans 10 or 12 depending on the substitution pattern of the 4-pentenyloxy radical. Substituted tetrahydropyrans 11 or 13 are formed in the minor 6-endo-trig cyclization. According to the data of competition kinetics, the observed stereoselectivities in free alkoxy radical cyclizations arise from steric interactions between the substituents in the transition state of the ring closure reactions. Alkyl substituents cause small differences in the measured relative rate constants of 5-exo cyclizations which are reminiscent of the data obtained from the rearrangements of alkyl-substituted 5-hexenyl radicals. Likewise, a stereochemical model for oxygen radical cyclization is proposed where the pentenyloxy chain adopts a six-membered, chairlike transition state with the alkyl substituents preferentially situated in the pseudoequatorial positions leading to 2,5-trans-, 2,4-cis-, and 2,3-trans-substituted tetrahydrofurfuryl radicals 8 as the major intermediates.
- Hartung,Gallou
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- Switchable synthesis of 2,5-dimethylfuran and 2,5-dihydroxymethyltetrahydrofuran from 5-hydroxymethylfurfural over Raney Ni catalyst
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Raney-type metals (Cu, Co and Ni) were employed to catalyze hydrogenation of 5-hydroxymethylfurfural. Switchable synthesis of 2,5-dimethylfuran and 2,5-dihydroxymethyltetrahydrofuran was achieved with 96% and 88.5% yield respectively over Raney Ni, demonstrating high feasibility for industrialization. The excellent yields can be explained by the fact that Raney Ni facilitates the hydrogenation reaction but has limited deoxygenation ability at low temperature, while high temperature promotes the deoxygenation step. The reaction pathway was analyzed by time course experiments and HMF hydrogenation over model catalysts was performed. The reaction mechanism related to the respective catalytic sites was discussed and proposed, which has great implications in the design of efficient and non-noble metal catalysts.
- Kong, Xiao,Zhu, Yifeng,Zheng, Hongyan,Dong, Fang,Zhu, Yulei,Li, Yong-Wang
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- Robust and recyclable nonprecious bimetallic nanoparticles on carbon nanotubes for the hydrogenation and hydrogenolysis of 5-hydroxymethylfurfural
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Selective hydrogenation and hydrogenolysis of 5-hydroxymethylfurfural were performed with carbon nanotube-supported bimetallic Ni-Fe (Ni-Fe/CNT) catalysts. The combination of Ni and Fe in an appropriate atomic ratio of Ni/Fe (2.0) significantly increased the selectivity to 2,5-furandimethanol or 2,5-dimethylfuran depending on the reaction temperature. The selectivities to 2,5-furandimethanol and 2,5-dimethylfuran were as high as 96.1 % at 383 K and 91.3 % at 473 K, respectively. The characterization results confirmed that bimetallic particles with sizes less than 7 nm were formed on the catalyst. Several key molecules related to 5-hydroxymethylfurfural transformation were used to investigate the product distribution and reaction pathway. The results indicated that the formation of Ni-Fe alloy species is beneficial to the selective cleavage of the C-O bond. Recycling experiments showed that the catalyst can be easily separated with a magnet and reused several times without significant loss of activity.
- Yu, Lili,He, Le,Chen, Jin,Zheng, Jianwei,Ye, Linmin,Lin, Haiqiang,Yuan, Youzhu
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- Metal-free hydrogenation catalyzed by an air-stable borane: Use of solvent as a frustrated Lewis base
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In recent years 'frustrated Lewis pairs' (FLPs) have been shown to be effective metal-free catalysts for the hydrogenation of many unsaturated substrates. Even so, limited functional-group tolerance restricts the range of solvents in which FLP-mediated reactions can be performed, with all FLP-mediated hydrogenations reported to date carried out in non-donor hydrocarbon or chlorinated solvents. Herein we report that the bulky Lewis acids B(C6Cl5)x(C6F5)3-x (x=0-3) are capable of heterolytic H2 activation in the strong-donor solvent THF, in the absence of any additional Lewis base. This allows metal-free catalytic hydrogenations to be performed in donor solvent media under mild conditions; these systems are particularly effective for the hydrogenation of weakly basic substrates, including the first examples of metal-free catalytic hydrogenation of furan heterocycles. The air-stability of the most effective borane, B(C6Cl5)(C6F5)2, makes this a practically simple reaction method.
- Scott, Daniel J.,Fuchter, Matthew J.,Ashley, Andrew E.
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- Facile gas-phase hydrodeoxygenation of 2,5-dimethylfuran over bifunctional metal-acid catalyst Pt-Cs2.5H0.5PW12O40
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2,5-Dimethylfuran is deoxygenated to n-hexane with 100% yield on a bifunctional Pt/C-Cs2.5H0.5PW12O40 catalyst under very mild conditions (90 °C, 1 bar H2) in a one-step gas-phase process. A proposed mechanism includes a sequence of hydrogenolysis, hydrogenation and dehydration steps occurring on Pt and proton sites of the bifunctional catalyst.
- Althikrallah, Hanan,Kozhevnikova, Elena F.,Kozhevnikov, Ivan V.
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- In situ generation of water-stable and -soluble ruthenium complexes of pyridine-based chelate-ligands and their use for the hydrodeoxygenation of biomass-related substrates in aqueous acidic medium
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The complexes [Ru(2,2′-dipicolylamine)(OH2)3](OTf)2 and [Ru(6,6′-bis(aminomethyl)-2,2′-bipyridine)(OH2)2](OTf)2 can be prepared by reaction of 2,2′-dipicolylamine or 6,6′-bis(aminomethyl)-2,2′-bipyridine with [RuIII(DMF)6](OTf)3 in aqueous medium. During the reaction an in situ reduction from a paramagnetic RuIII to a diamagnetic RuII-complexes occurs with one equivalent of DMF acting as the reducing agent for two ruthenium centres by its reaction with water and decomposition to dimethylammonium triflate and CO2 generating an additional equivalent of HOTf in the process. The complex solutions are active as catalysts for the hydrogenation of 2,5-hexanedione and 2,5-dimethylfuran to 2,5-hexanediol and 2,5-dimethyltetrahydrofuran with both complexes realizing very high yields (>95% combined yield of the two products with the selectivity determined as a function of added acid co-catalyst). The 2,2′-dipicolylamine complex is stable to 150?°C, while the 6,6′-bis(aminomethyl)-2,2′-bipyridine complex is stable to 200?°C allowing the in situ hydrolysis of 2,5-dimethylfuran to the 2,5-hexanedione and thus direct conversion to the same products in up to 78% combined yield. The effects of co-solvents, acid co-catalysts and temperature on catalyst activity, decomposition and stability are explored.
- Minard, Thomas A.,Oswin, Christopher T.,Waldie, Fraser D.C.,Howell, Jennifer K.,Scott, Benjamin M.T.,Mondo, Domenico Di,Sullivan, Ryan J.,Stein, Benjamin,Jennings, Michael,Schlaf, Marcel
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- Direct Visualization of Substitutional Li Doping in Supported Pt Nanoparticles and Their Ultra-selective Catalytic Hydrogenation Performance
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It has only recently been established that doping light elements (lithium, boron, and carbon) into supported transition metals can fill interstitial sites, which can be observed by the expanded unit cell. As an example, interstitial lithium (intLi) can block H filling octahedral interstices of palladium metal lattice, which improves partial hydrogenation of alkynes to alkenes under hydrogen. In contrast, herein, we report intLi is not found in the case of Pt/C. Instead, we observe for the first time a direct ‘substitution’ of Pt with substitutional lithium (subLi) in alternating atomic columns using scanning transmission electron microscopy-annular dark field (STEM-ADF). This ordered substitutional doping results in a contraction of the unit cell as shown by high-quality synchrotron X-ray diffraction (SXRD). The electron donation of d-band of Pt without higher orbital hybridizations by subLi offers an alternative way for ultra-selectivity in catalytic hydrogenation of carbonyl compounds by suppressing the facile CO bond breakage that would form alcohols.
- Chen, Tianyi,Foo, Christopher,Zheng, Jianwei J. W.,Fang, Huihuang,Nellist, Peter,Tsang, Shik Chi Edman
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- Highly active bifunctional Pd-Co9S8/S-CNT catalysts for selective hydrogenolysis of 5-hydroxymethylfurfural to 2,5-dimethylfuran
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A series of Pd-Co bimetallic catalysts were smoothly synthesized using sulfur-modified carbon nanotubes (S-CNT) as support by impregnation method. Those catalysts were characterized by XRD, XPS, TEM, SEM, H2-TPR, TGA, and nitrogen adsorption-de
- Liao, Weiping,Zhu, Zhiguo,Chen, Naimeng,Su, Ting,Deng, Changliang,Zhao, Yuchao,Ren, Wanzhong,Lü, Hongying
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- Temperature-Dependent Stereoselectivity and Hydrogen Deuterium Kinetic Isotope Effect for γ-Hydrogen Transfer to 2-Hexyloxy Radical. The Transition State for the Barton Reaction
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The diastereomers of 5-deuterio-2-hexanol, prepared stereospecifically from acetol and lactic acid by using fermentation procedures, have been subjected to the Barton reaction with Ag2CO3/Br2 in pentane over the temperature range -8.65 to 30.05 deg C.The
- Green, Mark M.,Boyle, Barbara A.,Vairamani, M.,Mukhopadhyay, Triptikumar,Saunders, William H.,et al.
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- Generation of alkyl hypochlorites in oxidation of alcohols with carbon tetrachloride catalyzed by vanadium and manganese compounds
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Primary alcohols and diols with various structures were subjected to transformations into esters, aldehydes, ketones, and lactones under the action of carbon tetrachloride in the presence of manganese compounds (MnCl 2, MnO2, Mn(OAc)2, Mn(acac)3) and vanadium compounds (VCl5, V2O5, VO(acac) 2) as catalysts. These transformation proceeded with the involvement of alkyl hypochlorites, which were generated in the course of oxidation of alcohols with carbon tetrachloride catalyzed by manganese or vanadium compounds. The optimum molar ratios between the catalyst and reagents were determined, and the reaction conditions for the highly selective synthesis of esters, aldehydes, ketones, and lactones from alcohols were found.
- Khusnutdinov,Shchadneva,Baiguzina,Lavrentieva,Dzhemilev
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- A continuous flow process for the production of 2,5-dimethylfuran from fructose using (non-noble metal based) heterogeneous catalysis
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The abundant carbohydrate fructose is converted into two biofuel molecules, namely 2,5-dimethylfuran (DMF) and ethyl levulinate (EL) in a simple cascade flow reactor. With an overall yield of 85% (38.5% of 2,5-dimethylfuran and 47% of ethyl levulinate), the main remainder is unconverted fructose. The two column flow reactor set-up enables the adjustment of temperatures and reaction times in such a way that the reactive intermediate hydroxymethylfurfural (5-HMF) is generated in optimal yields and converted into the stable DMF immediately. The process is so simple and fast (20 min) that economic and sustainable production of these fuels and platform chemicals can be envisioned. A remaining minor char formation is regarded to be the major problem which has to be addressed by catalyst development.
- Braun, Max,Antonietti, Markus
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- Ga+-catalyzed hydrosilylation? about the surprising system Ga+/HSiR3/olefin, proof of oxidation with subvalent Ga+and silylium catalysis with perfluoroalkoxyaluminate anions
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Already 1 mol% of subvalent [Ga(PhF)2]+[pf]- ([pf]- = [Al(ORF)4]-, RF = C(CF3)3) initiates the hydrosilylation of olefinic double bonds under mild conditions. Reactions with HSiMe3 and HSiEt3 as substrates efficiently yield anti-Markovnikov and anti-addit
- Barthélemy, Antoine,Glootz, Kim,Hanske, Annaleah,Krossing, Ingo,Scherer, Harald
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p. 439 - 453
(2022/01/22)
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- Acidic metal-organic framework empowered precise hydrodeoxygenation of bio-based furan compounds and cyclic ethers for sustainable fuels
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Target synthesis of hydrocarbons from abundant biomass is highly desired for sustainable aviation fuels (SAFs) to meet the need for both net zero carbon emission and air pollution control. However, precise hydrodeoxygenation (PHDO) of bio-based furan compounds and cyclic ethers to isomerically pure alkanes remains a challenge in heterogenous catalysis, which usually requires delicate control of the distribution of acid and metal catalytic sites in nanoconfined space. Here we show that a nanoporous acidic metal-organic framework (MOF), namely MIL-101-SO3H, enables one-pot PHDO reactions from furan-derivative oxygenates to solely single-component alkanes by just mechanical mixing with commercial Pd/C towards highly efficient and highly selective hydrocarbon production. The superior performance of such tandem catalysts can be attributed to the preferential adsorption of oxygenate precursors and expulsion of deoxygenated intermediates benefiting from Lewis acid sites embedded in the MOF. The strong Br?nsted acidity of MIL-101-SO3H is contributed by both the -SO3H groups and the adsorbed H2O, which makes it a water-tolerant solid acid for durable PHDO processes. The simplicity of mechanical mixing of different heterogenous catalysts allows the modulation of the tandem catalysis system for optimization of the ultimate catalytic performance. This journal is
- Gao, Xiang-Yu,He, Hai-Long,Li, Zhi,Liu, Dong-Huang,Wang, Jun-Jie,Xiao, Yao,Yi, Xianfeng,Zeng, Tengwu,Zhang, Yue-Biao,Zheng, Anmin,Zhou, Si-Yu
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supporting information
p. 9974 - 9981
(2021/12/27)
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- Hydrogen-Bonding Catalyzed Ring-Closing C?O/C?O Metathesis of Aliphatic Ethers over Ionic Liquid under Metal-Free Conditions
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O-heterocycles have wide applications, and their efficient and green synthesis is very interesting. Herein, we report hydrogen-bonding catalyzed ring-closing metathesis of aliphatic ethers to O-heterocycles over ionic liquid (IL) catalyst under metal- and solvent-free conditions. The IL 1-butylsulfonate-3-methylimidazolium trifluoromethanesulfonate ([SO3H-BMIm][OTf]) is discovered to show outstanding performance, better than the reported catalysts. An interface effect plays an important role in mediating the reaction rate due to the immiscibility between the products and the IL catalyst, and the products can be spontaneously separated. NMR analysis and DFT calculation suggest that a pair of cation and anion of [SO3H-BMIm][OTf] could form three strong H-bonds with an ether molecule, which catalyze the ether transformation via a cyclic oxonium intermediate. A series of O-heterocycles including tetrahydrofurans, tetrahydropyrans, morpholines and dioxane can be obtained from their corresponding ethers in excellent yields (e.g., >99 %). This work opens an efficient and metal-free way to produce O-heterocycles from aliphatic ethers.
- Wang, Huan,Zhao, Yanfei,Zhang, Fengtao,Wu, Yunyan,Li, Ruipeng,Xiang, Junfeng,Wang, Zhenpeng,Han, Buxing,Liu, Zhimin
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supporting information
p. 11850 - 11855
(2020/05/16)
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- METHOD FOR THE HYDRODEOXYGENATION OF OXYGENATED COMPOUNDS TO UNSATURATED PRODUCTS
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The invention relates to methods of hydrodeoxygenation of oxygenated compounds into compounds with unsaturated carbon-carbon bonds, comprising the steps of: a) providing a reaction mixture comprising, an oxygenated compound containing one or more of a hydroxyl, keto or aldehyde group, an ionic liquid, a homogeneous metal catalyst, and carbon monoxide or a carbon monoxide releasing compound, b) reacting said reaction mixture under a H2 atmosphere at acidic conditions at a temperature between 180 and 250 °C and a pressure between 10 and 200 bar.
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Page/Page column 18-19
(2021/01/23)
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- Synthesis of Tetrahydroisoquinolines through an Iron-Catalyzed Cascade: Tandem Alcohol Substitution and Hydroamination
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Rapid assembly of saturated nitrogen heterocycles - the synthetically more challenging variants of their aromatic relatives - can expedite the synthesis of biologically relevant molecules. Starting from a benzylic alcohol tethered to an unactivated alkene, an iron-catalyzed tandem alcohol substitution and hydroamination provides access to tetrahydroisoquinolines in a single synthetic step. Using a mild iron-based catalyst, the combination of these operations forms two carbon-nitrogen bonds and provides a unique annulation strategy to access this valuable core.
- Marcyk, Paul T.,Cook, Silas P.
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p. 6741 - 6744
(2019/09/07)
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- Nonclassical Mechanism in the Cyclodehydration of Diols Catalyzed by a Bifunctional Iridium Complex
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1,4- and 1,5-diols undergo cyclodehydration upon treatment with cationic N-heterocyclic carbene (NHC)–IrIII complexes to give tetrahydrofurans and tetrahydropyrans, respectively. The mechanism was investigated, and a metal-hydride-driven pathway was proposed for all substrates, except for very electron-rich ones. This contrasts with the well-established classical pathways that involve nucleophilic substitution.
- González Miera, Greco,Bermejo López, Aitor,Martínez-Castro, Elisa,Norrby, Per-Ola,Martín-Matute, Belén
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supporting information
p. 2631 - 2636
(2019/02/01)
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- Toward an Integrated Conversion of 5-Hydroxymethylfurfural and Ethylene for the Production of Renewable p-Xylene
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The use of biomass as a solution to satisfy the pressing needs for a fully sustainable biocommodity industry has been explored for a long time. However, limited success has been obtained. In this study, a highly effective two-stage procedure for the direct preparation of para-xylene (PX) from 5-hydroxymethylfurfural (HMF) and formic acid in one pot is described; these chemicals are two of the major bio-based feedstocks that offer the potential to address urgent needs for the green, sustainable production of drop-in chemical entities. The use of a robust, efficient heterogeneous catalyst, namely, bimetallic Pd-decorated Au clusters anchored on tetragonal-phase zirconia, is crucial to the success of this strategy. This multifunctional catalytic system can not only facilitate a low-energy-barrier H2-free pathway for the rapid, nearly exclusive formation of 2,5-dimethylfuran (DMF) from HMF but also enable the subsequent ultraselective production of PX by the dehydrative aromatization of the resultant DMF with ethylene. With increasing pressure around the world to move toward a bio-based economy, it is essential that industrially important commodity chemicals can be readily accessed from biomass resources. Para-xylene (PX) synthesis is one such target that is being actively pursued through the development of several biorefinery schemes based on integrated biomass processing. Significant progress has recently been achieved either in the selective synthesis of biorenewable PX from Diels-Alder-like coupling of ethylene with 2,5-dimethylfuran (DMF) or making DMF from 5-hydroxymethylfurfural (HMF) using hydrogen as the terminal reductant. However, a green and direct conversion of HMF, an essential feedstock source for future biorefinery schemes, into PX has yet to be developed. We have established an integrated process that directly converts HMF to PX in a highly compact and hydrogen-independent manner, thereby providing a new perspective on the potential of advanced biorefinery technologies. Cao and colleagues describe an alternative strategy for producing para-xylene through a more sustainable method than the current bio-based approaches. The strategy relies on an integrated conversion of 5-hydroxymethylfurfural with formic acid and ethylene, made possible by the use of a single multifunctional catalyst based on bimetallic Pd-decorated Au deposited on tetragonal-phase zirconia. The proposed process is particularly appealing because it is fully fossil independent, implying a viable and greener biorefinery scheme.
- Tao, Lei,Yan, Tian-Hao,Li, Wenqin,Zhao, Yi,Zhang, Qi,Liu, Yong-Mei,Wright, Mark M.,Li, Zhen-Hua,He, He-Yong,Cao, Yong
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supporting information
p. 2212 - 2227
(2018/10/02)
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- Poisoning of Ru/C by homogeneous Br?nsted acids in hydrodeoxygenation of 2,5-dimethylfuran via catalytic transfer hydrogenation
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It has been proposed that the combination of metal and acid sites is critical for effective ring opening of biomass-derived furans to linear molecules, a reaction that holds promise for the production of renewable polymer precursors and alkanes. In this work, we use 2,5-dimethylfuran (DMF) as a model compound to investigate hydrogenolysis and hydrogenation pathways using a combination of H2SO4 and Ru-mediated catalytic transfer hydrogenation in 2-propanol. Acid-catalyzed hydrolytic ring opening of DMF to 2,5-hexanedione (HDN) occurs readily at 80?°C with a selectivity of 89% in 2-propanol. Over Ru/C, HDN is fully converted after only 2?h at 80?°C, forming a mixture of both ring-closed products (～68% total yield), i.e., 2,5-dimethyltetrahydrofuran (DMTHF) and 2,5-dimethyl-2,3-dihydrofuran (DMDHF), as well as ring opened products (～28% total yield), i.e., 2,5-hexanediol (2,5-HDL) and 2-hexanol (HOL). Rather than observing sequential hydrolysis/hydrogenation reactions, we observe severe suppression of metal chemistry when having both Ru/C and H2SO4 in the reaction system. While minor leaching of Ru occurs in the presence of mineral acids, X-ray photoelectron spectroscopy coupled with CO chemisorption studies suggest that the primary cause of the lack of Ru-mediated chemistry is poisoning by strongly adsorbed sulfate species. This hypothesis is supported by the observation of Ru-catalyzed chemistry when replacing H2SO4 with Nafion, a solid Br?nsted acid, as sulfonic acid groups tethered to the polymer backbone cannot adsorb on the metal sites.
- Gilkey, Matthew J.,Vlachos, Dionisios G.,Xu, Bingjun
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p. 327 - 335
(2017/06/19)
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- Hydrodeoxygenation of Furylmethane Oxygenates to Jet and Diesel Range Fuels: Probing the Reaction Network with Supported Palladium Catalyst and Hafnium Triflate Promoter
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Catalytic hydrodeoxygenation of furylmethane oxygenates to high carbon branched chain jet and diesel fuel range alkanes under mild reaction conditions is a promising strategy for energy-efficient production of fuels with minimal C-C cracking to undesired products. Here, we report that a strong Lewis acidic promoter can overcome the energy barrier for furylmethane hydrodeoxygenation at lower temperature. Furan rings of furylmethanes are first hydrogenated to fully saturated cyclic ethers by a hydrogenation catalyst, which then undergo facile ring opening and deoxygenation by the promoter. A cyclic intermediate between ethereal O and the Lewis acidic metal center, assisted by the triflate ligand of the promoter, is formed in the ring-opening step. Probing the reaction pathway with symmetric single furan ring surrogate molecules suggests that the promoter is necessary for the ring opening. Deoxygenation of ring-opened oxygenates takes place more quickly for single furan ring surrogates than for the multiple furan ring furylmethanes. A maximum 97% jet fuel range alkanes with 93% selectivity in C15H32 and C14H30 is achieved from C15-furylmethane under optimal conditions. The yield and selectivity of alkanes with desired carbon numbers can be tuned using furylmethanes with tailored carbon chains, furan numbers, and a carbon center that minimizes C-C cracking. (Chemical Equation Presented).
- Dutta, Saikat,Saha, Basudeb
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p. 5491 - 5499
(2017/08/17)
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- Selective Hydrogenation of 2-Methylfuran and 2,5-Dimethylfuran over Atomic Layer Deposited Platinum Catalysts on Multiwalled Carbon Nanotube and Alumina Supports
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2-Methylfuran (2MF) and 2,5-dimethylfuran (DMF) were hydrogenated in the vapor phase to the corresponding tetrahydrofurans, linear 2-ketones, and alcohols over Pt nanoparticles supported on multiwalled carbon nanotubes (MWCNTs) and alumina by atomic layer deposition. The hydrogenation behavior of sub-nanometer Pt deposited on alumina was influenced by the acidity of the support. Relative to a commercial Pt/C catalyst, the Pt/MWCNT catalyst was found to contain similarly sized Pt nanoparticles that display a broader size distribution and significantly more n-alkanes than oxygenates during hydrogenation of these alkyl-substituted furans.
- Kang, Jungshik,Liang, Xinhua,Guliants, Vadim V.
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p. 282 - 286
(2017/02/05)
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- TRANSITION METAL(S) CATALYST SUPPORTED ON NITROGEN-DOPED MESOPOROUS CARBON AND ITS USE IN CATALYTIC TRANSFER HYDROGENATION REACTIONS
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The present invention discloses a novel transition metal(s) catalyst supported on nitrogen-doped mesoporous carbon and a process for the preparation of the same. Further, the present invention discloses use of transition metal(s) supported on nitrogen- doped mesoporous carbon catalyst in catalytic transfer hydrogenation reaction. The invention also discloses an improved process for the synthesis of 2,5-Dimethylfuran (DMF) and 2-Methylfuran (MF) from 5-hydroxymethylfurfural (HMF) and furfural respectively, using alcohols as hydrogen donor over a transition metal supported on nitrogen-doped mesoporous carbon, especially ruthenium supported on nitrogen-doped mesoporous carbon without using any co-catalysts.
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Page/Page column 17; 21-28
(2017/03/28)
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- METHOD FOR PRODUCING TETRAHYDROFURAN COMPOUND
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PROBLEM TO BE SOLVED: To provide a method for efficiently producing a tetrahydrofuran compound having a hydroxymethyl group by suppressing the hydrogenolysis of a hydroxymethyl group in a step of obtaining a tetrahydrofuran compound by reducing a furan compound. SOLUTION: There is obtained a corresponding tetrahydrofuran compound by reducing a furan compound represented by the following general formula (1) by bringing into contact with a palladium catalyst in a hydrogen atmosphere in the coexistence of a base. (wherein, Ra represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a formyl group or a hydroxymethyl group; Rb represents a formyl group or a hydroxymethyl group; R1 and R2 each independently represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a hydroxyl group; and R1 and R2 may be bonded together to form a ring.) SELECTED DRAWING: None COPYRIGHT: (C)2016,JPOandINPIT
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Paragraph 0088; 0090; 0096
(2017/01/17)
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- PROCESS FOR THE PREPARATION OF 2, 5-DIMETHYLEFURAN AND FURFURYL ALCOHOL OVER RUTHENIUM SUPPORTED CATALYSTS
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The present invention relates to an improved process for the preparation of 2.5-dimethylfuran and furfuryl alcohol over ruthenium supported catalysts. Further, the present invention disclosed a process for the selective hydrogenolysis of biomass derived 5-hydroxymethylfurfural (HMF) into 2.5-dimethylfuran (DMF) using Ru nanoparticles supported on NaY zeolite as a catalyst.
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Paragraph 0075
(2016/12/16)
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- METHOD FOR REDUCING HYDROXYMETHYLFURFURAL (HMF)
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The invention relates to the conversion of renewable biomass resources into valuable compounds. More specifically, it relates to the selective valorisation of 5-(hydroxymethyl)furfural into useful chemicals and fuels. Provided is a method of reducing hydroxymethylfurfural (HMF), comprising the steps of: - providing a starting material comprising HMF in a solvent into a reactor; - providing H2 into the reactor; and - contacting the starting material with a catalyst, wherein said catalyst is copper-zinc alloy in a nanoparticulate form.
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Page/Page column 14; 15; 16; 17; 18; 19; 20
(2016/04/09)
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- Rational design of Ni-based catalysts derived from hydrotalcite for selective hydrogenation of 5-hydroxymethylfurfural
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Selective hydrogenation of 5-hydroxymethylfurfural (HMF) is of great importance for future energy and chemical supply. Herein, we propose for the first time that non-noble Ni-Al2O3 catalysts derived from hydrotalcite-like compounds can efficiently and selectively convert HMF into 2,5-dimethylfuran (DMF), 2,5-dimethyltetrahydrofuran (DMTHF) and 2,5-dihydroxymethyltetrahydrofuran (DHMTHF). Homogeneous elemental distributions of the hydrotalcite-like precursor facilitate good dispersion of Ni and Al2O3 species and strong interaction between them over the resulting catalysts. The catalysts therefore exhibited superior reactivity. Through fine modulation of surface metal-acid bifunctional sites and control of reaction conditions, high yields of DMF (91.5%), DMTHF (97.4%) and DHMTHF (96.2%) can be diversely achieved. The results demonstrate the feasibility of Ni catalysts for selective hydrogenation of C=O, C=C and C-O bonds, which have great potential for biomass utilization.
- Kong, Xiao,Zheng, Runxiao,Zhu, Yifeng,Ding, Guoqiang,Zhu, Yulei,Li, Yong-Wang
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p. 2504 - 2514
(2015/04/22)
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- Copper-zinc alloy nanopowder: A robust precious-metal-free catalyst for the conversion of 5-hydroxymethylfurfural
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Noble-metal-free copper-zinc nanoalloy (2. It is also possible to convert 10 wt % HMF solutions in CPME, with an excellent DMF yield of 90 %. Milder temperatures favor selective (95 %) formation of 2,5-furandimethanol (FDM). The one-pot conversion of fructose to valuable furan-ethers was also explored. Recycling experiments for DMF production show remarkable catalyst stability. Transmission electron microscopy (TEM) characterization provides more insight into morphological changes of this intriguing class of materials during catalysis.
- Bottari, Giovanni,Kumalaputri, Angela J.,Krawczyk, Krzysztof K.,Feringa, Ben L.,Heeres, Hero J.,Barta, Katalin
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p. 1323 - 1327
(2015/05/05)
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- Hydrodeoxygenation of 2,5-hexanedione and 2,5-dimethylfuran by water-, air-, and acid-stable homogeneous ruthenium and iridium catalysts
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The complexes [(4′-Ph-terpy)Ru(H2O)3](OTf)2 and [(4′-Ph-terpy)Ir(OTf)3] have been evaluated as catalysts for the conversion of 2,5-hexanedione and 2,5-dimethylfuran to hydrodeoxygenated products in aqueous acidic medium at elevated temperature (150-225 °C) under hydrogen gas (5.5 MPa). These two substrates form part of a value chain leading from C6 sugars to 2,5-hexanediol, 2,5-dimethyltetrahydrofuran, and hexane, which can be generated by the homogeneously acting ruthenium catalyst in up to 69%, 80%, and 10% yield, respectively, while at T > 175 °C the iridium system decomposes to a highly active but heterogeneously acting coating in the reactor defeating the premise of a homogeneous catalyst system. The deactivation and decomposition pathway of both catalysts leads to the formation of a series of isostructural complexes [M(4′-Ph-terpy)2]n+ (M = Fe, Ni, Ru, Ir; n = 2, 3) characterized by ESI-MS and single crystal X-ray crystallography, in which the source of the Fe and Ni is the 316SS reactor body.
- Sullivan, Ryan J.,Latifi, Elnaz,Chung, Benjamin K.-M.,Soldatov, Dmitriy V.,Schlaf, Marcel
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p. 4116 - 4128
(2015/02/19)
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- CATALYTIC SYNTHESIS OF REDUCED FURAN DERIVATIVES
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The present invention relates to catalytic synthesis of furan derivatives from alkoxymethylfurfural ethers or acyloxymethylfurfural esters. More particularly, the invention pertains to furan derivatives obtained by use of a multifunctional catalyst system to carry out both hydrogenation of furan starting material and hydrolysis of the reduced furan derivative in a single reaction. The process allows recovering and recycling of alcohol or acid from the reaction product.
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Paragraph 0061
(2014/11/13)
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