Efficient catalytic hydrogenolysis of glycerol using formic acid as hydrogen source

We describe a sustainable, cost-effective, and highly efficient H2-free protocol for catalytic hydrogenolysis of glycerol to 1,2-propanediol (1,2-PDO) using formic acid (FA) as the H2 source. The process is catalyzed by an earth-abundant and robust Cu-based metal oxide catalyst, in which the high performance of the Cu catalyst for the in situ generation of H2 gas in the system by highly selective decomposition of FA in an aqueous medium is essential. The activity test results showed that a synergy effect of well-dispersed Cu and amphoteric ZrO2 is essential for FA decomposition as well as for glycerol conversion to 1,2-PDO. The Cu content of the Cu/ZrO2 catalyst prepared by the oxalate gel method has a significant role in the FA-mediated glycerol conversion to 1,2-PDO, and a Cu content of 20 wt% on ZrO2 was identified as the optimum Cu content. Moreover, the creation and maintenance of high component dispersion is essential for high glycerol hydrogenolysis activity of the Cu/ZrO2 system. Because selective hydrogenolysis with minimum use of external fossil-fuel H2 is a critical issue in the realization of biorefinery concepts, the procedure described here is expected to be of broad applicability in biomass use.

Biorenewable formic acid as a convenient H2 source and cheap and earth-abundant Cu-based catalysts can be used for the facile conversion of glycerol to 1,2-propanediol (PDO). The present findings form the basis of cost-competitive production of 1,2-PDO from glycerol and the development of new sustainable, affordable processes for the targeted conversion of bio-derived feedstock, with minimum use of external fossil-fuel-based H2 sources.Figure optionsDownload as PowerPoint slide