Selective hydrogenolysis and hydrogenation using metal catalysts directly modified with metal oxide species

Production of biomass-derived chemicals requires the decrease of oxygen content in substrates because building blocks in biomass refinery have high oxygen content. C-O hydrogenolysis is one of the useful reactions for decreasing the oxygen content. On the other hand, selective C-O hydrogenolysis is essential in order to obtain a specific product in high yield since the building blocks are over-functionalized and contain a variety of C-O bonds. Recently, selective C-O hydrogenolysis was advanced by the development of surface modification of noble metal particles with metal oxide species. The modified catalysts have been also applied to the selective hydrogenation of carbonyl and carboxyl groups, which are also common functional groups in biomass-derived building blocks. This review deals with the performance, the structure of the active sites, and the reaction mechanism over the catalysts with direct bonds between noble metal particles and metal oxide species.