Modulating Cobalt Valence Cycle Energetics for Selective Biomass Polyol Oxidation

Abstract Biomass‐derived intermediates often contain multiple alcohol groups, and their selective oxidation is crucial for effective valorization. CoOOH is a promising electrocatalyst for polyol upgrading, converting alcohols into valuable products, such as carboxylic acids. However, the Co ³⁺ /Co ⁴⁺ transition limits its performance in dehydrogenation and C─C bond cleavage, requiring high overpotentials. Using glycerol as a model polyol, this study demonstrates that heteroatom co‐doping of CoOOH with Cu and Fe enhances the energetics of Co oxidation cycle, improving glycerol oxidation reaction (GOR) efficiency at lower overpotentials. The Cu‐Fe co‐doped CoOOH exhibits a favorable synergy between efficiency and selectivity, exhibiting 95.5% formic acid selectivity, a productivity of 1.55 mmol cm ⁻² h ⁻¹ , and a Faradaic efficiency of 84.7%. Mechanical analyses reveal the complementary roles of Cu and Fe doping: Cu facilitates glycerol adsorption and supports the Co ²⁺ /Co ³⁺ /Co ⁴⁺ redox cycle, while Fe enhances catalytic activity through the Co ³⁺ /Co ⁴⁺ transition, and aids in OH ⁻ replenishment during catalyst regeneration. The heteroatom Cu‐Fe co‐doping strategy optimizes glycerol oxidation by improving glycerol adsorption, promoting dehydrogenation, facilitating C─C bond cleavage, mitigating over‐oxidation, and enhancing active site regeneration. The findings gained from this study provide a valuable framework for the rational design of more efficient, non‐precious metal‐based catalysts for biomass valorization.