Bimetallic Co-Mn catalyzed chemselective oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid

• A nitrogen-doped porous carbon-supported Co-Mn dual-metal (CoMn-NC) catalyst was developed for enhanced HMF cascade oxidation . • 99 % HMF conversion and 95 % FDCA selectivity were achieved at 80 °C using t-BuOOH as the oxidant. • The dominant oxidation route (HMF→DFF→FFCA→FDCA) was identified through time-resolved experiments. • Comprehensive characterizations (e.g., XPS , TEM) were employed to investigate microstructural evolution and Co/Mn valence state variations in CoMn-NC catalysts pre- and post-reaction. The development of efficient catalysts for the stepwise oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-diformyl furan (DFF), 5-hydroxymethyl-2-furancarboxylic acid (HMFCA), 5-Formyl-2-furancarboxylic acid (FFCA) or 2,5-furandicarboxylic acid (FDCA) is critical for biomass valorization. Herein, we reported a bimetallic Co-Mn catalyst anchored on nitrogen-doped porous carbon, which was used for the oxidation of HMF to FDCA, avoiding the use of high temperature and high-pressure oxygen. High FDCA selectivity (>95 %) was achieved through reaction condition optimization. And HMF→DFF→FFCA→FDCA was considered to be the main reaction pathway during the whole oxidation process. Additionally, the chemical environment of the constituent elements of the used catalyst was analyzed by XPS. TEM revealed that the catalyst retained its porous structure and excellent metal dispersion after the reaction. This structural stability was corroborated by sustained >90 % FDCA selectivity over five consecutive reaction cycles. This work established a dual-metal synergy strategy for multi-step oxidation pathways, offering insights into the design of robust catalysts for biomass-derived platform molecule upgrading.