Reduced oxygen-deficient CuWO4 with Ni catalyzed selective hydrogenolysis of cellulose to ethylene glycol

The effective and selective conversion of cellulose to valuable fuels and chemicals is highly attractive. In this paper, we prepared a catalyst with the adjacent surface Cu° and oxygen-deficient WO x (2 < x < 3) species by reduction of CuWO 4 precursor, and such catalyst coupled with Ni/activated carbon (AC) attained high yield (71 wt%) and good cycling performances in catalyzing one-step hydrothermal conversion of cellulose to ethylene glycol (EG), highly superior to the performances on physically mixed Ni/C, Cu/C and WO 3 . The increased Cu doping amounts led to a higher ratio of the lower valence state W (V or IV) to the high valence W(VI) as indicated by XPS, XRD, and TPR-H 2 analyses. The oxygen vacancies on the hydrogen-reduced CuWO 4 sample dramatically increased, probably due to the benefits from the substantial dissociated H• on the neighboring Cu° center. The EG yields from cellulose are shown to be proportional to the concentrations of oxygen vacancies on WO x , which catalyzes the important elementary retro-aldol step reaction via adsorbing C 6 sugar intermediates in a specific way. It is inferred that Cu introduction is mainly used to create more oxygen vacancies on the WO x surface that helps adsorbing oxygenates, while Ni fast hydrogenates of hydroxyacetaldehyde to EG and avoids coking, constructing a multi-functional synergistic catalytic process from converting of cellulose to EG in the high-temperature water