Highly efficient conversion of biomass-derived furanic compounds into alkyl diols by selective hydrogenolysis using non-noble metal catalysts with tunable surface oxygen vacancies

Abstract

Production of alkyl diols from biomass-derived furanic compounds by hydrogenolysis is a promising route to the fabrication of bio-based polyesters and polyurethanes. However, it faces many challenges such as the use of noble metal catalysts, or low hydrogenolysis activity of the furan rings and poor product selectivity with non-noble metal catalysts. In this work, non-noble metal catalysts Cu-Co3O4 (CuCox) catalysts were modified by magnesium, obtaining CuCoxMgy catalysts with tunable surface oxygen vacancies (OV). The CuCoxMgy catalysts demonstrated greatly improved activity and selectivity (approx. 50 %), comparable to those of noble metal catalysts, in the hydrogenolysis of furfuryl alcohol into 1,5-pentanediol (1,5-PeD). The obtained CuCoxMgy catalysts are even superior to the noble metal catalysts in terms of production rate or productivity. Extensive characterizations including XAS, EPR and XPS revealed that magnesium significantly promotes the formation of Co2+-OV pair sites on the catalyst surface, which simultaneously activate furan ring and hydroxyl group in furfuryl alcohol, leading to the efficient and selective cleavage of the C2-O1 bond to form 1,5-PeD. The CuCoxMgy catalysts also exhibited high activity and selectivity in hydrogenolysis of various other biomass-derived furanic compounds towards ring-opening products.