From Heat to Electrons: Bridging Heterogeneous Liquid-Phase Thermal and Electrocatalytic Oxidation of Ethylene Glycol...

The selective oxidation of alcohols under thermal and electrocatalytic conditions presents a promising route to value-added chemicals using sustainable energy sources. We establish mechanistic convergence between heterogeneous liquid-phase thermal oxidation of ethylene glycol (EG) and its electrocatalytic oxidation reaction (EGOR) using mesostructured Co₃O₄ synthesized via hard templating as a catalyst. Comprehensive catalytic performance assessments and ab initio molecular dynamics simulations reveal analogous surface intermediates and pathways in both regimes, resulting in the same product distribution. Co³⁺ centers and OH^- species facilitate oxidation via proton-coupled electron transfer (PCET), with molecular oxygen or the applied anodic potential regenerating active sites. Product selectivity to glycolate, formate, and oxalate is governed by temperature, EG concentration, pH, applied O₂ pressure, or potential. Surface and bulk characterization confirm the robustness of the spinel structure, enabling multiple catalyst recycling. These insights provide a first mechanistic framework connecting heterogeneous thermal and electrocatalytic oxidation over non-noble metal oxide catalysts, paving the way for designing multi-functional materials for chemical synthesis under electrothermal conditions.