Carbon-regulated MnxOy catalysts from Mn-MOF-74: Synergistic effects on glucose oxidation to formic acid

The catalytic oxidation of glucose to formic acid (FA) represents a crucial route for biomass valorization. Metal–organic framework (MOF)-derived carbon composites offer exceptional tunability for catalyst design. Herein, a series of carbon-regulated Mn x O y /C catalysts from Mn-MOF-74 precursors via controlled calcination atmospheres and temperatures, achieving satisfactory performance in glucose-to-FA conversion. Comprehensive characterization reveals that the carbon matrix plays a synergistic effect: dispersing Mn x O y nanoparticles to enhance substrate accessibility, and preventing Mn leaching to improve stability. The FA yield is determined by fine-tuning key parameters: the (Mn 2+ +Mn 3+ )/Mn valence ratio and Mn x O y particle size. Combined DFT and experimental analyses demonstrate that Mn valence states determine reaction kinetics: Mn 3 O 4 exhibits elevated glucose adsorption energy and reduced formic acid (FA) desorption energy, while MnO displays an opposing trend, rationalizing the activity differences. This work establishes a carbon-mediated synergy strategy for designing efficient Mn-based catalysts in biomass oxidation upgrading.