10299-30-6Relevant academic research and scientific papers
Biphasic catalytic conversion of fructose by continuous hydrogenation of HMF over a hydrophobic ruthenium catalyst
Yang, Yanliang,Du, Zhongtian,Ma, Jiping,Lu, Fang,Zhang, Junjie,Xu, Jie
, p. 1352 - 1356 (2014)
The production of chemicals directly from sugars is an important step in biomass conversion. Herein, tetrahydro-2,5-furandimethanol (THFDM), obtained from fructose, is formed by using a combination of acid and hydrophobic Ru/SiO2 in a water/cyclohexane biphasic system. Two key factors enable the high selectivity towards THFDM: modifying the hydrogenation catalyst so that it has hydrophobic properties, and the continuous hydrogenation of generated 5-(hydroxymethyl)furfural in the cyclohexane phase. Moreover, the selectivity towards THFDM is found to depend strongly on the acid catalyst used. Divide and conquer: A method for direct catalytic conversion of fructose to tetrahydro-2,5-furandimethanol (THFDM) via 5-(hydroxymethyl)furfural (HMF) is reported. High selectivity towards THFDM is achieved by using a catalyst combination of acid and a hydrophobic ruthenium catalyst (Ru/SiO2-TM) in a water/cyclohexane biphasic system by continuous hydrogenation of generated HMF. The use of the hydrophobic Ru/SiO2-TM is the key, as it prevents hydrogenation of fructose to mannitol and sorbitol in the water phase.
Direct conversion of carbohydrates to diol by the combination of niobic acid and a hydrophobic ruthenium catalyst
Duan, Ying,Zhang, Jun,Li, Dongmi,Deng, Dongsheng,Ma, Lu-Fang,Yang, Yanliang
, p. 26487 - 26493 (2017)
Tetrahydro-2,5-furandimethanol (THFDM) was obtained directly from a wide variety of carbohydrates by the combination of niobic acid and a hydrophobic ruthenium catalyst. Fructose, glucose, and polysaccharides consisting of fructose or glucose could be converted to THFDM in one-step. The selectivity to THFDM was kept around 60% while the glucose conversion varied from 9% to 49%. The as-synthesized niobic acid was characterized by TEM, N2 adsorption/desorption, XRD, NH3-TPD and FT-IR spectra of adsorpted pyridine. The niobic acid was proved to have medium and strong acid sites with a high Br?nsted/Lewis ratio, which played a great role for keeping high THFDM selectivity using glucose as a substrate.
Mechanistic study on -C-O- and -C-C- hydrogenolysis over Cu catalysts: Identification of reaction pathways and key intermediates
Kühne, Benjamin,Vogel, Herbert,Meusinger, Reinhard,Kunz, Sebastian,Kunz, Markwart
, p. 755 - 767 (2018/02/14)
Important petro-based polyol compounds with a longer carbon chain, such as oligohydroxy hexanes (e.g. 1,2- and 1,6-hexanediol or 1,2,6-hexanetriol), require at least three to four synthesis steps. Replacing this complex chemistry by a one-pot reaction via -C-O- bond cleavage from sugars would be a significant breakthrough for the use of renewable feedstocks. Cu is known for its dehydroxylation (deoxygenation) properties, yielding the desired products from sugars. In this joint research between academic and industrial chemistry, we have identified so far unknown intermediate products and present the first mechanism that explains the selective cleavage of OH-groups over copper. Strong interactions between polyols, unsaturated species and the copper surface are observed. Stable five-membered rings are formed with Cu via two vicinal OH-groups of the polyol reactant that makes these OH-groups inert to -C-O- bond cleavage. Adjacent free OH-groups in close proximity to the catalyst are dehydroxylated (deoxygenated). We further show that degradation of polyols not only occurs via commonly cited retro-aldol reactions. The formation of acid intermediates with subsequent decarboxylation is validated as a new pathway for -C-C- bond cleavage to short-chain polyols and CO2. The proposed mechanisms for -C-O- and -C-C- bond cleavage elucidate why hydrogenolysis reactions require high hydrogen pressure (up to 200 bar) to suppress the degradation of sugars and obtain high yields of deoxy C6 products. With this knowledge, the improvement of a standard commercial Cu-RANEY catalyst under optimized reaction conditions was shown. In contrast to alumina-supported Cu, the Cu-Al alloy in a RANEY-type catalyst shows selective -C-O- bond cleavage properties while maintaining the C6 carbon chain. These new insights into the transformation of sugars to value added commodities show the potential for new approaches in future biorefinery concepts.
The selective hydrogenation of biomass-derived 5-hydroxymethylfurfural using heterogeneous catalysts
Alamillo, Ricardo,Tucker, Mark,Chia, Mei,Pagan-Torres, Yomaira,Dumesic, James
experimental part, p. 1413 - 1419 (2012/06/15)
The products produced by hydrogenation of biomass-derived 5-hydroxymethylfurfural (HMF) are potential sustainable substitutes for petroleum-based building blocks used in the production of chemicals. We have studied the hydrogenation of HMF over supported Ru, Pd, and Pt catalysts in monophasic and biphasic reactor systems to determine the effects of the metal, support, solution phase acidity, and the solvent to elucidate the factors that determine the selectivity for hydrogenation of HMF to its fully hydrogenated form of 2,5-di-hydroxy-methyl-tetrahydrofuran (DHMTHF). We show that the selectivity to DHMTHF is affected by the acidity of the aqueous solution containing HMF. The major by-products observed are C6-polyols formed from the acid-catalyzed degradation and subsequent hydrogenation of 2,5-dihydroxymethylfuran (DHMF), an intermediate hydrogenation product of HMF to DHMTHF. The highest yields (88-91%) to DHMTHF are achieved using Ru supported on materials with high isoelectric points, such as ceria, magnesia-zirconia, and γ-alumina. Supported catalysts containing Pt and Pd at the same weight percent as Ru are not as active for the selective hydrogenation to DHMTHF.
