Hydrophilic mesoporous poly(ionic liquid)-supported Au-Pd alloy nanoparticles towards aerobic oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid under mild conditions

Design of stable high-performance heterogeneous catalysts has become crucial for efficient catalytic conversion of renewable biomass into high value-added chemicals. Noble metal alloy nanoparticles (NPs) are of great interest due to their unique tunable structures and high activity. In this study, Au-Pd alloy NPs supported on hydrophilic mesoporous poly(ionic liquid) (MPIL) exhibited encouragingly high performance in the aerobic oxidation of biomass-derived 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) in water under mild conditions. Nearly complete conversion of HMF is attained at a low temperature of 90 °C under atmospheric O₂, resulting in 99% FDCA yield and high turnover number (TON) of up to 350. After reaction, the catalyst can be facilely recovered and reused with stable activity. Surface wettability plays a dominant role in the oxidation of HMF to FDCA, and synergistic alloy effect accounts for high activity. The results also show that MPILs are a promising support platform to achieve stable and efficient metal NPs through task-specific design of functional monomers.