LAUSR

Abstract The hydrogenolysis of various polyols and ethers over a Pt/WO3/Al2O3 catalyst was investigated. The hydrogenolysis rate of a C O bond at a secondary carbon was higher than that at a primary carbon, indicating that a hydroxyl (OH) group at a primary carbon played an important role in the dissociation of a C O bond. Moreover, the dissociation position of the C O bond in alcohols and ethers strongly depended on the stability of the carbocation intermediate, and hydrogenolysis via a secondary carbocation as an intermediate proceeded preferentially to that via a primary carbocation. The kinetics of the hydrogenolysis of C3 polyols were also investigated. The reaction orders with respect to the concentrations of glycerol, 1,2- and 1,3-propanediol were almost the same. In contrast, different reaction orders with respect to the H2 pressure were observed for the hydrogenolysis of C3 polyols with or without vicinal OH groups, indicating that the dissociation of a C O bond at primary and secondary carbons proceeded via completely different mechanisms. These investigations suggested that both the structure and position of a substrate on the catalyst surface must be controlled for highly selective hydrogenolysis.