Release Time:2019-03-11  Hits:

Indexed by: Journal Papers

Date of Publication: 2014-10-01

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

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

Volume: 234

Issue: ,SI

Page Number: 200-207

ISSN: 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.