Ring-Opening Transformation of 5-Hydroxymethylfurfural Using a Golden Single-Atomic-Site Palladium Catalyst

Abstract

The development of function-integrated catalysts to enable scalable and efficient biomass valorization is an important topic. Here, a stepwise methodology was developed to fabricate novel supported Au–Pd bimetallic catalysts featuring immobilized well-defined on-surface nanoarchitectures (Pd∧Au). This was achieved by an atomic decoration of a trace amount of Pd (Pd/Au molar ratio of 0.01–0.02) on the surface of 2 nm Au nanoparticle (NP, 0.86 wt %) preanchored to titania. Benefiting from their unique structural merits and the cooperative interplay among the selective hydrogenation activity furnished by the ultrasmall Pd∧Au NPs and prominent Lewis acidity endowed by TiO2, Pd0.02∧Au/TiO2 exhibits excellent activity with 100% conversion and over 90% selectivity and stability (turnover number up to 48 300) toward controlled ring-opening conversion of 5-hydroxymethylfurfural and related furanic compounds to the corresponding di- and triketone-type products under mild conditions (120 °C, 10 bar of H2). The results offer great promise for the future advancement of next-generation multifunctional solid catalysts by tuning the interface structure and precise decoration of active sites with required functionalities.