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 MnO2 (MnO2/CF) catalyst by in-situ growth of MnO2 nanoparticles on blocky CF, and the catalytic activity of MnO2/CF for the oxidation of HMF to FDCA was evaluated. Under mild reaction conditions, the MnO2/CF catalyst achieved 99.8% conversion of HMF and 97.0% yield of FDCA, which was well beyond the catalytic performance of single MnO2. 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 MnO2. The synergistic interaction of CF and MnO2 effectively enhanced specific surface area, surface acid-base sites, oxygen vacancy concentration, and charge transfer efficiency of MnO2/CF composite, contributing to favorable catalytic performance. Additionally, the MnO2/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.