Selective hydrogenolysis of 5-hydroxymethylfurfural to 5-methylfurfural over Au/TiO2.

5-Methylfurfural (MF) is a critical commodity chemical used as food additive and synthetic intermediate. Opening a sustainable route towards highly selective synthesis of MF from 5-hydroxymethylfurfural (HMF) is of great significance, but has demonstrated extremely challenging. Herein, we report an efficient process for the selective production of MF from HMF over an anatase-supported gold catalyst (Au/a-TiO 2). During the hydrogenolysis of HMF, the desired C O bond is maintained and MF can be obtained in a high yield of 83.1 %, exhibiting excellent stability both in batch and flow operation. A combination of experimental and theoretical analyses attribute the superior performance of Au/a-TiO 2 to the synergistic effect of limited H access, low adsorption of reactants, and avoiding condensation, driven by the high concentration of oxygen vacancies in the support. This study highlights a novel approach of tailoring the coverage of active species for the selective transformation of renewable compounds into high-value-added chemicals. [Display omitted] • Selective production of MF from HMF via direct hydrogenolysis of the hydroxyl group using the Au/a-TiO 2 catalyst. • The C=O functional group was preserved under reductive conditions and MF can be obtained in a high yield of 83.1%. • The Au/a-TiO 2 catalyst shows high activity, remarkable selectivity, and excellent stability both in batch and flow operation. • The synergistic effect of limited H access, low adsorption of reactants, high concentration of oxygen vacancies. • This study paves the way for the design of new bifunctional catalysts toward selective hydrogenolysis of biomass. [ABSTRACT FROM AUTHOR]