From Heat to Electrons: Bridging Heterogeneous Liquid-Phase Thermal and Electrocatalytic Oxidation of Ethylene Glycol over Co3O4

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, 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.