Theoretical Insight into Catalytic Mechanism of Methanol Electrooxidation: Water Activation and Depoisoning Reactions

Based on density functional theory, the catalytic mechanism of methanol oxidation reaction (MOR) on Pt electrodes is systematically investigated. Water activation and depoisoning are main factors in performance controlling of MOR. Pt electrodes exhibit activities in water activation via thermodynamic pathway, thereby facilitating methanol oxidation at low potentials. We proposed the reasonable reaction network and revealed the MOR are regulated by depoisoning steps. Methanol dehydrogenation becomes achievable at a low potential, manifesting itself through multiple pathways, with the elevated overpotential in MOR primarily attributed to water decomposition. Crucially, the depoison involving carbon-containing intermediates and OH/O emerge as the rate-limiting steps.