Efficient Catalytic Oxidation of 5-Hydroxymethylfurfural to 2,5-Furandicarboxylic Acid Using a Natural Mineral Vermiculite-Loaded Gold–Palladium Bimetallic Catalyst

Upgrading the bio-derived platform chemical 5-hydroxymethylfurfural (HMF) into the high value-added bioplastic monomer 2,5-furandicarboxylic acid (FDCA) is a promising pathway for biomass conversion. In this work, the natural and abundant available mineral vermiculite was employed as a carrier for loading a Au-Pd bimetal catalyst. Due to the high dispersion of bimetallic nanoparticles, this synthesized vermiculite-supported Au-Pd bimetal catalyst revealed excellent catalytic performance for the aerobic oxidation of HMF to FDCA. By adjusting the ratio of Au and Pd metals, the catalytic performance of the catalyst can be optimized. Finally, 100% HMF conversion and 99.9% FDCA yield could be obtained under the conditions of Au/Pd = 2/1, 2 h, 2 MPa O2, and 100 °C. The catalyst revealed good stability, and the FDCA yield can be maintained at 90.1% after five recycle usages. The physicochemical properties of the synthesized catalysts were characterized by various characterization methods. It could be concluded that the high dispersion and alloying effect of bimetallic nanoparticles promoted the activation of reactants and intermediates, resulting in the effective production of FDCA. This study could provide ideas and references for the development and utilization of natural minerals and also offer a new way to realize the efficient conversion of HMF to FDCA under green conditions.