Development of a Ru/C catalyst for glycerol hydrogenolysis in combination with an ion-exchange resin

The combination of Ru/C and Amberlyst ion-exchange resin is effective for the dehydration and hydrogenation (denoted as hydrogenolysis) of glycerol to 1,2-propanediol under mild reaction conditions (393 K). A Ru/C catalyst prepared by using active carbon with a low surface area (∼250 m2/g) showed better performance than that prepared by using active carbon with a high surface area. In addition, treatment of Ru/C catalysts prepared from Ru(NO)(NO3)3 with Ar flowing at the appropriate temperature enhanced the performance compared to that of the commercially available Ru/C catalysts. This temperature treatment can be influenced by the decomposition of Ru precursor salt and aggregation of Ru metal particles. In addition, the degradation reaction as a side-reaction to C1 and C2 compounds of glycerol hydrogenolysis was more structure-sensitive than the hydrogenolysis reaction, and the selectivity of hydrogenolysis was lower on smaller Ru particles. The combination of Ru/C with the Amberlyst resin enhanced the turnover frequency of 1,2-propanediol formation drastically, and this indicates that 1,2-propanediol can be formed mainly by dehydration of glycerol to acetol catalyzed by Amberlyst and subsequent hydrogenation of acetol to 1,2-propanediol catalyzed by Ru/C.

Ru/C catalysts prepared from Ru(NO)(NO3)3 and active carbon with a low surface area (∼250 m2/g) exhibited higher activity and selectivity in the glycerol conversion to propanediols than commercially available Ru/C catalysts (Ru/C*) in combination with an ion-exchange resin. Characterization results suggested highly dispersed Ru metal particles on the graphite phase can be effective. Figure optionsDownload as PowerPoint slide