Xi:Irritant;1003-38-9Relevant articles and documents
One-Step catalytic transformation of carbohydrates and cellulosic biomass to 2,5-dimethyltetrahydrofuran for liquid Fuels
Yang, Weiran,Sen, Ayusman
, p. 597 - 603 (2010)
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.
Effects of Water on the Copper-Catalyzed Conversion of Hydroxymethylfurfural in Tetrahydrofuran
Liu, Yifei,Mellmer, Max A.,Alonso, David Martin,Dumesic, James A.
, p. 3983 - 3986 (2015)
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.
Selective hydrogenation of 5-ethoxymethylfurfural over alumina-supported heterogeneous catalysts
Ras, Erik-Jan,Maisuls, Sergio,Haesakkers, Paul,Gruter, Gert-Jan,Rothenberg, Gadi
, p. 3175 - 3185 (2009)
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
Pd/C-catalyzed reactions of HMF: Decarbonylation, hydrogenation, and hydrogenolysis
Mitra, Joyee,Zhou, Xiaoyuan,Rauchfuss, Thomas
, p. 307 - 313 (2015)
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.
Heterogeneous Ketone Hydrodeoxygenation for the Production of Fuels and Feedstocks from Biomass
Jenkins, Rhodri W.,Moore, Cameron M.,Semelsberger, Troy A.,Sutton, Andrew D.
, p. 2807 - 2815 (2017)
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.
Support Effect of Ru Catalysts for Efficient Conversion of Biomass-Derived 2,5-Hexanedione to Different Products
Hua, Manli,Song, Jinliang,Huang, Xin,Hou, Minqiang,Fan, Honglei,Zhang, Zhaofu,Wu, Tianbin,Han, Buxing
, p. 7685 - 7693 (2021)
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.
Formic Acid-Assisted Selective Hydrogenolysis of 5-Hydroxymethylfurfural to 2,5-Dimethylfuran over Bifunctional Pd Nanoparticles Supported on N-Doped Mesoporous Carbon
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
, p. 6807 - 6815 (2021)
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?.
ORGANOTINS AS ETHERIFICATION CATALYSTS. II. CATALYTIC CONVERSION OF ALCOHOLS TO OPEN-CHAIN AND CYCLIC ETHERS BY ORGANOTIN TRICHLORIDES
Tagliavini, Giuseppe,Marton, Daniele,Furlani, Donatella
, p. 1187 - 1196 (1989)
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.
Mechanistic study of a one-step catalytic conversion of fructose to 2,5-dimethyltetrahydrofuran
Grochowski, Matthew R.,Yang, Weiran,Sen, Ayusman
, p. 12363 - 12371 (2012)
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
Zinc-assisted hydrodeoxygenation of biomass-derived 5-hydroxymethylfurfural to 2,5-Dimethylfuran
Saha, Basudeb,Bohn, Christine M.,Abu-Omar, Mahdi M.
, p. 3095 - 3101 (2014)
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.
