Selective Hydrodeoxygenation for the Synthesis of Oxygen-Containing Chemicals: Fossil-Based Substrates to Biomass-Based Ones

Hydrodeoxygenation of oxygen-containing aliphatic compounds has emerged together with the concept of biomass refinery. The hydrogenolysis of C-O bond is a useful and central reaction for hydrodeoxygenation. There are two different approaches in C-O hydrogenolysis: indirect multi step method (dehydrogenation-dehydration-hydrogenation and dehydration-hydrogenation routes) and direct C-O scission. The indirect route proceeds on conventional catalysts for C-O hydrogenolysis such as Ru- and Cu-based ones. The catalysts for the direct C-O hydrogenolysis have been recently developed. In this review, the key to controlling selectivity in hydrogenolysis of sterically hindered and unhindered C-O bonds has been described in the cases of glycerol, erythritol, and 1,4-anhydroerythritol.