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Highlights: [•] Coupling ethanol dehydrogenation and MA hydrogenation gave H2 and heat compensation. [•] Ethanol dehydrogenation/maleic anhydride hydrogenation are competitive reactions. [•] Cu/Al2O3 catalyst favored the formation of γ-butyrolactone and ethyl acetate. [•] Cu/ZnO and Cu/ZrO2 catalysts favored formation of diethyl succinate and acetaldehyde. [Copyright &y& Elsevier]

Abstract: Cu/ZnO/MO x (MO x =Al2O3, TiO2, and ZrO2) catalysts were prepared by the coprecipitation method. Crystal ZnO and amorphous Al2O3, TiO2, and ZrO2 presented in both calcined and reduced Cu/ZnO/MO x catalysts. After reduction, CuO species were converted to metallic copper (Cuo). The acidities of the Cu/ZnO/MO x catalysts were in an order of Cu/ZnO/Al2O3 >Cu/ZnO/ZrO2 >Cu/ZnO/TiO2 >Cu/ZnO. The catalytic activities of Cu/ZnO/MO x catalysts in the gas phase hydrogenolysis of glycerol were studied at 240–300°C under 0.1MPa of H2. The acid sites of Cu/ZnO/MO x catalysts catalyzed the dehydration of glycerol and the metallic copper catalyzed the hydrogenation reactions. Cu/ZnO/TiO2 catalyst favored the formation of 1,3-propanediol and ethylene glycol with maximum selectivities of 10% and 37%, respectively, at high reaction temperatures. Cu/ZnO/Al2O3 and Cu/ZnO/ZrO2 catalysts exhibited good selectivity toward hydroxyacetone ranging from 81% to 40% at reaction temperatures of 240–300°C, which were higher than those of Cu/ZnO and Cu/ZnO/TiO2 catalysts. The composition of Cu/ZnO/MO x catalysts significantly affected the product selectivity in the gas phase hydrogenolysis of glycerol. [Copyright &y& Elsevier]

Abstract: Cu/ZnO/TiO2 catalysts were prepared via the coprecipitation method. The catalysts were characterized by X-ray diffraction, X-ray photoelectron spectrometry, temperature programmed reduction, and N2 adsorption. The catalytic activity of Cu/ZnO/TiO2 catalyst in gas phase hydrogenation of maleic anhydride in the presence of n-butanol was studied at 235–280°C and 1MPa. The conversion of maleic anhydride was more than 95.7% and the selectivity of tetrahydrofuran was up to 92.7%. At the same time, n-butanol was converted to butyraldehyde and butyl butyrate via reactions, namely, dehydrogenation, disproportionation, and esterification. There were two kinds of CuO species present in the calcined Cu/ZnO/TiO2 catalysts. At a lower copper content, the CuO species strongly interacted with ZnO and TiO2; at a higher copper content, both the surface-anchored and bulk CuO species were present. The metallic copper (CuO) produced by the reduction of the surface-anchored CuO species favored the deep hydrogenation of maleic anhydride to tetrahydrofuran. The deep hydrogenation activity of Cu/ZnO/TiO2 catalyst increased with the decrease of crystallite sizes of CuO and the increase of microstrain values. Compensations of reaction heat and H2 in the coupling reaction of maleic anhydride hydrogenation and n-butanol dehydrogenation were distinct. [Copyright &y& Elsevier]