Selective hydrogenolysis of C-O bonds using the interaction of the catalyst surface and OH groups.

Hydrogenolysis of C-O bonds is becoming more and more important for the production of biomass-derived chemicals. Since substrates originated from biomass usually have high oxygen content and various kinds of C-O bonds, selective hydrogenolysis is required. Rhenium or molybdenum oxide modified rhodium and iridium metal catalysts (Rh-ReO(x), Rh-MoO(x), and Ir-ReO(x)) have been reported to be effective for selective hydrogenolysis. This review introduces the catalytic performance and reaction kinetics of Rh-ReO(x), Rh-MoO(x), and Ir-ReO(x) in the hydrogenolysis of various substrates, where selectivity is especially characteristic. Based the model structure of the catalysts and the reaction mechanism, the role of the oxide components is to make the interaction between the OH groups in the substrates and the catalyst surface, and the role of metal components is to dissociate hydrogen molecule heterolytically to give hydride and proton.