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Indexed by:期刊论文

Date of Publication:2016-09-01

Journal:JOURNAL OF ENERGY CHEMISTRY

Included Journals:SCIE、EI、ISTIC、Scopus

Volume:25

Issue:5

Page Number:782-792

ISSN No.:2095-4956

Key Words:CuMgAl hydrotalcites; Solid base catalyst; Hydrogenolysis; Highly concentrated cellulose

Abstract:The Cu-containing catalysts were synthesized via thermal treatment of the CuMgAl hydrotalcite with a fixed metal ratio at various calcination temperatures. The bi-functional solid base catalysts exhibited high activity for the hydrogenolysis of highly concentrated cellulose. The hydrotalcite precursors and the calcined samples were characterized by means of X-ray diffraction (XRD), thermogravimetric analysis (TG), N-2 adsorption-desorption, temperature-programmed reduction of H-2 (H-2-TPR), temperature- programmed desorption of CO2 (CO2-TPD) and dissociative N2O adsorption. The characterization results indicated that the transformation of structure was caused by the increasing calcination temperature, which could further influence the numbers of the base sites and metal active sites in the CuMgAl catalysts. The hydrogenolysis of cellulose was systematically investigated over different catalytic systems. With the CuMgAl-600 catalyst, complete conversion of cellulose can be accomplished and the highest yield obtained is 81.4%, with total polyols yields obtained are 59.1% for the C2-C3 polyols. In addition, either the in-situ hydroxyl or the hydrated OH- due to the "memory effect" of hydrotalcite as Bronsted bases, was proved to exhibit promotional effect on the hydrogenolysis of cellulose, which could effectively substitute the effect of ionizing alkali. Furthermore, it is noteworthy that the conversion of cellulose could maintain up to 90.2% with unobvious formation of coke-like precipitates when the cellulose concentration reached a high level of 18%. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.