Modulated Oxygen Reduction Activity on Ordered Mesoporous Nitrogen-doped Carbon-supported Co–Mn Spinel Oxide for Electrochemical Carbon Dioxide Capture

Abstract

Electrochemical CO₂ capture technology holds promise for CO₂ utilization from industrial flue gases. However, its practical application is currently hindered by the lack of efficient and CO-tolerant cathodic catalysts for the oxygen reduction reaction (ORR). In this work, we propose an electronic structure modulation strategy to enhance the ORR activity of CO-tolerant Co₂MnO₄ catalyst by ordered mesoporous nitrogen-doped carbon (OMNC). The promoted charge transfer from Co₂MnO₄ to OMNC leads to an upshifted d-band center. This electronic modulation is accompanied by excellent ORR performance with a half-wave potential of 0.791 V and a high diffusion limited current density of 5.889 mA cm⁻². The catalyst enables efficient high-purity CO₂ production (98.6%) in a membrane electrode assembly electrolyzer, with minimal voltage increase under CO-containing atmosphere. This achievement highlights the significance of electronic structure engineering in designing robust ORR catalysts for practical electrochemical CO₂ capture systems.