High-selectivity room-temperature partial oxidation of methane to methanol enabled by electrochemical oxygen promotion on IrO2 catalysts

Abstract

The electrochemical conversion of methane into value-added chemicals offers a sustainable solution for utilizing abundant methane resources, yet achieving high selectivity for partial oxidation remains challenging. Here we demonstrate that employing an IrO₂ catalyst with CO₃²⁻ as an oxygen source enables efficient and selective electrochemical methane-to-methanol conversion at room temperature. Adsorption and dissociation of CO₃²⁻ on IrO₂(110) surfaces generates abundant active oxygen species, facilitating methane activation through surface-bound methoxy intermediates and thereby substantially enhancing methanol selectivity. Optimal conditions for methanol production are achieved within a potential range where interference from the competing oxygen evolution reaction is minimized, reaching a maximum methanol production rate of approximately 11.1 mmol g_cat⁻¹ h⁻¹ at 1.50 versus the reversible hydrogen electrode under continuous operation. Process modelling indicates an approximately 50% reduction in carbon emissions compared to conventional methanol production methods, emphasizing the sustainability and practical potential of this electrochemical methane oxidation approach.