141-06-0Relevant articles and documents
Highly efficient transformation of Γ-valerolactone to valerate esters over structure-controlled copper/zirconia catalysts prepared via a reduction-oxidation route
Liu, Shanshan,Fan, Guoli,Yang, Lan,Li, Feng
, p. 180 - 188 (2017)
Design and development of novel and efficient catalysts are crucial but challenging for the catalytic conversion of biomass and derivatives to fuels and chemicals. In this paper, a novel separate nucleation and aging steps assistant reduction-oxidation strategy was developed to synthesis CuO/ZrO2 complex precursor with homogeneously distributed Cu and Zr components, which can be used as an ideal precursor for the synthesis of highly dispersed Cu/ZrO2 catalyst. Characterization results revealed that homogeneous dispersion of CuO, high surface area of ZrO2 support with controlled porous structure, and strong interaction between CuO and ZrO2 in CuO/ZrO2 precursor could lead to the enhanced Cu dispersion and the formation of Cu+ active centers. The synthesized Cu/ZrO2 catalysts exhibited excellent catalytic performance (85.4% conversion of GVL and 98.0% selectivity of pentyl valerate) in the catalytic transformation of GVL to valerate esters, more efficient than that of Cu/ZrO2-CP and Cu/ZrO2-CH catalysts prepared via co-precipitation and chemisorption hydrolysis methods, respectively. The superior catalytic performance was mainly attributed to both the cooperation of Cu0 and Cu+ species and the highly dispersed surface Cu0, thereby improving the adsorption and polarization of C[dbnd]O bond in GVL and the following dissociation of H2 to produce active hydrogen for the hydrogenation step during the catalytic transformation of GVL. Moreover, such copper-based catalysts exhibited potential applications in the exploitation and utilization of biomass resources with significantly enhanced efficiency.
Polycyclic ketone monooxygenase from the thermophilic fungus Thermothelomyces thermophila: A structurally distinct biocatalyst for bulky substrates
Fürst, Maximilian J.L.J.,Savino, Simone,Dudek, Hanna M.,Castellanos, J. Rúben Gómez,De Souza, Cora Gutiérrez,Rovida, Stefano,Fraaije, Marco W.,Mattevi, Andrea
supporting information, p. 627 - 630 (2017/05/15)
Regio- and stereoselective Baeyer-Villiger oxidations are difficult to achieve by classical chemical means, particularly when large, functionalized molecules are to be converted. Biocatalysis using flavin-containing Baeyer-Villiger monooxygenases (BVMOs) is a wellestablished tool to address these challenges, but known BVMOs have shortcomings in either stability or substrate selectivity. We characterized a novel BVMO from the thermophilic fungus Thermothelomyces thermophila, determined its three-dimensional structure, and demonstrated its use as a promising biocatalyst. This fungal enzyme displays excellent enantioselectivity, acts on various ketones, and is particularly active on polycyclic molecules. Most notably we observed that the enzyme can perform oxidations on both the A and D ring when converting steroids. These functional properties can be linked to unique structural features, which identify enzymes acting on bulky substrates as a distinct subgroup of the BVMO class.
Catalytic conversion of biomass-derived levulinic acid to valerate esters as oxygenated fuels using supported ruthenium catalysts
Pan, Tao,Deng, Jin,Xu, Qing,Xu, Yang,Guo, Qing-Xiang,Fu, Yao
, p. 2967 - 2974 (2013/10/08)
The development of the catalytic conversion of biomass-based platform molecules into oxygenated fuel molecules is of great significance in order to reduce the dependence on fossil resources and to solve environmental problems. Alkyl valerate esters were proven to have the potential to be renewable additives of gasoline and diesel. In this work, we studied the hydrogenation of levulinic acid (LA) to valerate esters over supported Ru catalysts, and found that the acidity was an important factor for the catalyst performance. A bifunctional catalyst Ru/SBA-SO3H was developed as an active catalyst, and a highest yield of 94% to ethyl valerate (EV) was achieved. The catalyst was characterized by nitrogen adsorption/desorption methods, X-ray power diffraction (XRD), transmission electron spectroscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The effects of reaction conditions were comprehensively investigated and probable reaction pathways were proposed and verified. The conversion of LA to various alkyl valerate esters can also be catalyzed by the bifunctional catalyst. In addition, supported Cu and Ni catalysts were also screened under similar reaction conditions as Ru-based catalysts, and the combination of Ni/SBA-15 and SBA-SO3H exhibited activity for the conversion of LA to EV.
