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Indexed by:Journal Papers

Date of Publication:2014-10-01

Journal:2nd International Congress on Catalysis for Biorefineries (CatBior)

Included Journals:SCIE、EI、CPCI-S、Scopus

Volume:234

Issue:,SI

Page Number:200-207

ISSN No.:0920-5861

Key Words:Cu-Cr catalysts; Glycerol hydrogenolysis; 1,2-Propanediol; Synergetic effect

Abstract:Active species of Cu-Cr catalysts, prepared by an epoxide-assisted sol-gel route, were investigated for the hydrogenolysis of glycerol to 1,2-propanediol. Structural characterization of the catalysts was performed by means of N-2 physisorption, X-ray diffraction, H-2-temperature programmed reduction, high-resolution X-ray photoelectron spectroscopy, NH3-temperature programmed desorption, and N2O titration. On the basis of the characterizations, the copper species on the calcined Cu-Cr catalysts and the reduced Cu-Cr catalysts were assigned. Combined with reaction results, it was found that there was not similar trend in copper metal surface area and glycerol conversion, indicating that a two-site (Cu-0 and Cut) mechanism existed in the hydrogenolysis of glycerol over Cu-Cr catalysts. Besides, the maximum conversion of glycerol was obtained when the surface Cu-0/Cu+ ratio increased from 3.1 to 6.6, whereas decreased with increasing sequentially to 15.7, demonstrating that the appropriate surface Cu-0/Cu+ ratio was required for optimum hydrogenation activity. Thus, the synergetic effect between the Cu-0 and Cu+ was considered to be responsible for the high catalytic activity in the hydrogenolysis of glycerol, and that CuCr2O4 played a critical role in the glycerol hydrogenolysis reaction since it could function as a "hydrogen delivery bridge". (C) 2014 Elsevier B.V. All rights reserved.