41579-20-8Relevant articles and documents
Integrated catalytic process for biomass conversion and upgrading to C 12 furoin and alkane fuel
Liu, Dajiang,Chen, Eugene Y.-X.
, p. 1302 - 1310 (2014)
Report herein is an integrated catalytic process for conversion and upgrading of biomass feedstocks into 5,5′-dihydroxymethyl furoin (DHMF), through self-coupling of 5-hydroxymethyl furfural (HMF) via organocatalysis, and subsequently into n-C12H26 alkane fuel via metal-acid tandem catalysis. The first step of the process involves semicontinuous organocatalytic conversion of biomass (fructose, in particular) to the high-purity HMF. N-Heterocyclic carbenes (NHCs) are found to catalyze glucose-to-fructose isomerization, and the relatively inexpensive thiazolium chloride [TM]Cl, a Vitamin B1 analog, catalyzes fructose dehydration to HMF of good purity (>99% by HPLC), achieving a constant HMF yield of 72% over 10 semicontinuous extraction batch runs. Crystallization of the crude HMF from toluene yields the spectroscopically and analytically pure HMF as needle crystals. The second step of the process is the NHC-catalyzed coupling of C 6 HMF produced by the semicontinuous process to C12 DHMF; the most effective organic NHC catalyst produces DHMF in 93% or 91% isolated yield with an NHC loading of 0.70 mol % or 0.10 mol % at 60°C for 3 h under solvent-free conditions. The third step of the process converts C12 DHMF to linear alkanes via hydrodeoxygenation. With a bifunctional catalyst system consisting of Pd/C + acetic acid + La(OTf)3 at 250°C and 300 psi H2 for 16 h, DHMF has been transformed to liquid hydrocarbon fuel (78% alkanes), with a 64% selectivity to n-C12H26 and an overall C/H/O % ratio of 84/11/5.0.
Conversion of glucose into levulinic acid with solid metal(IV) phosphate catalysts
Weingarten, Ronen,Kim, Yong Tae,Tompsett, Geoffrey A.,Fernandez, Alejandro,Han, Kee Sung,Hagaman, Edward W.,Conner Jr., Wm. Curt,Dumesic, James A.,Huber, George W.
, p. 123 - 134 (2013)
We have prepared a series of well-characterized solid acid metal(IV) phosphate catalysts and tested them for the two-step dehydration/rehydration reaction to produce levulinic acid from glucose. The catalysts include zirconium (ZrP) and tin (SnP) phosphates with varying ratios of phosphorus to metal(IV). The structural, surface and bulk properties have been investigated using XRD, BET, XPS and 31P solid-state MAS NMR spectroscopy. ZrP is distinguished by a high concentration of polyphosphate species in the bulk phase, as well as increased hydroxyl groups on the surface. ZrP also shows a higher concentration of total acid sites and Bronsted acid sites compared to SnP, as determined by TPD measurements using gas-phase NH3 and isopropylamine. The catalyst selectivity is a function of the Bronsted to Lewis acid site ratio using either heterogeneous or homogeneous catalysts. Catalytic activity increases with increased Lewis acid sites. The Lewis sites mainly produce fructose via isomerization reactions and undesired degradation products (humins). HMF is produced on both Bronsted and Lewis sites, whereas levulinic acid is exclusively produced on Bronsted sites. Zirconium phosphate with a P/Zr molar ratio of 2 is favorable for levulinic acid production due to its inherently high surface area and enhanced Bronsted acidity. This study lays the grounds for further design of improved solid acid catalysts for aqueous phase production of HMF and levulinic from carbohydrates.
Tunable acidity in mesoporous carbons for hydrolysis reactions
Ferri,Campisi,Carniti,Gervasini,Shen
supporting information, p. 5873 - 5883 (2020/04/29)
A mesoporous carbon (CMC) has been treated under acidic conditions (32.5 wt% HNO3 at 10 °C or 40 °C) to prepare two new carbon samples (HCMC10 and HCMC40), which developed higher acidity in terms of quantity of sites and surface acid strength. The properties of the three carbons have been studied by using various techniques (N2 adsorption/desorption, TEM, XRPD, Raman spectroscopy, 13C NMR, 2D 1H-13C NMR, and XPS). Aromatic -COOH and -OH groups were identified as the main surface acid sites. Acid site density has been determined by pulse liquid-solid phase adsorption experiments carried out in different liquids. The samples retained acidity features in water, due to hydrophobicity of the surfaces, while acidity dropped when measured in methanol. From NH3-TPD analysis, a ranking of acid strength could be obtained: HCMC40 > HCMC10 > CMC. The good acidity of the carbon samples allowed them to act as catalysts in the hydrolysis reaction of sucrose to glucose and fructose. The catalytic activity of the carbon samples was compared to that of Amberlite, a commercial sulfated acid resin; the observed kinetic constant of HCMC40 was similar to that of Amberlite.
One-pot sol-gel synthesis of a phosphated TiO2 catalyst for conversion of monosaccharide, disaccharides, and polysaccharides to 5-hydroxymethylfurfural
Rao, Kasanneni Tirumala Venkateswara,Souzanchi, Sadra,Yuan, Zhongshun,Xu, Chunbao
supporting information, p. 12483 - 12493 (2019/08/12)
Catalytic conversion of biomass or biomass-derived carbohydrates into 5-hydroxymethylfurfural (HMF) is an important reaction for the synthesis of bio-based polymers, fuels, and other industrially useful products. In this study, phosphated titania (P-TiO2) catalysts with different phosphoric acid content were prepared through a simple one-pot sol-gel method and characterized by BET, XRD, FT-IR, NH3-TPD, py-FT-IR, and XPS techniques. The catalyst characterization results revealed the incorporation of phosphorus into the TiO2 framework in the form of a Ti-O-P bond. The P-TiO2 catalysts were applied to the conversion of glucose (≥10 wt%) into HMF in a biphasic water/THF reaction medium at 175 °C. Under optimized reaction conditions, 98% glucose conversion and 53% HMF yield were obtained over a 15P-TiO2 catalyst, and the catalyst was reused for several cycles with consistent activity and selectivity. The presence of both Br?nsted and Lewis acid sites, high BET surface area and pore volume, and high acidity could account for the high catalytic activity and selectivity. Besides, the 15P-TiO2 catalyst was also demonstrated to be active for the conversion of disaccharides (sucrose and cellobiose), polysaccharides (starch and microcrystalline cellulose) and industrial grade sugar syrups into HMF with reasonable yield.
