Temperature–Current Synergy in NiCo-Catalyzed Ethylene Glycol Oxidation

Ethylene glycol oxidation reaction (EGOR) is a promising anodic process to reduce the cell voltage compared with the oxygen evolution reaction (OER). Using ethylene glycol (EG) obtained from biomass-derived streams—such as cellulose, hemicellulose or lignocellulosic intermediates—and polyethylene terephthalate (PET) waste contributes to the development of circular-economy models. This study investigates EGOR on a non-noble NiCo bimetallic electrode, focusing on the effects of temperature and current density. The presence of EG reduces the initial potential by 240 mV at 25 °C, with a further 60 mV decrease at elevated temperatures, while the catalyst maintains high formate selectivity (>65%) across the tested conditions. Faradaic efficiency peaks at 100 mA cm−2 due to the full oxidation of formate to CO2 or the competing OER at higher current densities. There are no significant discrepancies between simulated and experimental faradaic efficiencies, although the presence of terephthalic acid (TPA) affects the shift in the electrode potential. Overall, these results highlight the relevance of EGOR for future applications in which EG derived from recycled plastics and renewable biomass can be electrochemically valorized within integrated biorefinery frameworks.