Hydrogenolysis of 1,2-propanediol for the production of biopropanols from glycerol.

Production of propanols from glycerol, which are known as biopropanols, requires catalysts for the hydrogenolysis of 1,2-propanediol, which has been easily derived from glycerol. It is found that the Rh/SiO(2) catalysts modified with ReO(x) species exhibited high activity and selectivity in the hydrogenolysis of 1,2-propanediol to propanols with low selectivity to degradation products and high stability. The optimized Rh--ReO(x)/SiO(2) (Re/Rh=0.5) catalyst gave high yields of 1-propanol (66 %) and propanols (1-propanol +2-propanol) (85 %) in the hydrogenolysis of 1,2-propanediol. In addition, the catalyst was applicable to the one-pot conversion of glycerol to propanols. The structure of Rh metal particles with attached ReO(x) clusters is suggested from the catalyst characterization. It is proposed that 1,2-propanediol hydrogenolysis proceeds by the hydrogenolysis of the alkoxide species on Re with hydrogen species on the Rh metal surface.