In-situ growth of MnO2 on hierarchical porous carbon foam with enhanced oxygen vacancy concentration and charge transfer for efficient catalytic oxidation of 5-hydroxymethylfurfural

The catalytic oxidation of biomass-derived 5-hydroxymethylfurfural (HMF) to prepare 2,5-furandicarboxylic acid (FDCA) is a promising route to produce biomass-based functional materials. It is significant to develop non-noble metal-based catalysts for efficient conversion of HMF to FDCA. In this study, a facile and green technology was developed to prepare hierarchical porous carbon foam (CF)-supported MnO 2 (MnO 2 /CF) catalyst by in-situ growth of MnO 2 nanoparticles on blocky CF, and the catalytic activity of MnO 2 /CF for the oxidation of HMF to FDCA was evaluated. Under mild reaction conditions, the MnO 2 /CF catalyst achieved 99.8% conversion of HMF and 97.0% yield of FDCA, which was well beyond the catalytic performance of single MnO 2 . The results indicated that the CF with hierarchical porous structure and oxygen-containing groups could facilitate the diffusion of reactant molecules and regulate the crystal structure and morphology of MnO 2 . The synergistic interaction of CF and MnO 2 effectively enhanced specific surface area, surface acid-base sites, oxygen vacancy concentration, and charge transfer efficiency of MnO 2 /CF composite, contributing to favorable catalytic performance. Additionally, the MnO 2 /CF catalyst showed promising stability and reusability. This work provides new insights into the development of efficient, stable, and economical non-noble metal-based catalysts for catalytic conversion of biomass-based chemicals.