Near-infrared plasmonic activation of molecular oxygen for selective oxidation of biomass derivatives

Abstract Upgrading biomass feedstock into higher-value chemicals is central to improve the sustainability of the chemical industry and to reduce its dependence on fossil raw materials. Heterogeneous photocatalysts are promising for the oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA), a biomass-derived molecular platform for biopolymers, but their FDCA selectivity is negligible without the aid of a base. Here we present a plasmonic photocatalyst integrating TiN nanocubes and bimetallic RuPt nanoparticles that in base-free conditions exhibits complete HMF conversion and selective FDCA formation due to an unconventional mechanism of molecular oxygen activation. This unique reactivity is enhanced by both photothermal heating and hot electrons, whose contribution is confirmed by kinetic isotopic effect experiments. Density functional theory calculations support a scenario in which the activated nanoparticle–oxygen complex facilitates the rate-determining step and enables an improved FDCA selectivity. Our results demonstrate the potential of plasmonic photocatalysts in the catalytic transformation of biomass.