New reaction schemes for the production of biomass-based chemicals created by selective catalytic hydrogenolysis: Catalysts with noble metal and tungsten

Bimetallic catalysts containing noble metal and tungsten are effective in C-O hydrogenolysis reactions. Three types of C-O hydrogenolysis reactions have been reported: one is the direct hydrogenolysis of C-O bond neighboring a terminal OH group such as tetrahydrofurfuryl alcohol to 1,5-pentanediol. This catalysis is common for Rh-MO_x (M = Mo, Re, and W) catalysts. Water solvent and low reaction temperature (~393 K) are applied. Another is deoxydehydration + hydration of vicinal cis -diols to mono-alcohols such as 1,4-anhydroerythritol to 3- hydroxytetrahydrofuran. The combination of WO 3 and noble metal, especially Pd, is effective in this reaction. The reaction proceeds in non-water solvent (1,4-dioxane) and at high temperature (453-473 K). The other is selective production of 1,3-propanediol from glycerol over Pt-W catalysts. The combination of Pt and W is specifically effective. The reaction is operated in the presence of water at high temperature (~453 K). The proposed mechanism is a variant of dehydration + hydrogenation, and the intermediate of 1,3-propanediol formation is stabilized by W species.