Efficient CO2 reduction to CO + CH4 at CuCo@NC cathode integrated with CH3OH oxidation to methylal at Pt anode in an ionic liquid electrolyte

Abstract

Electroreduction of CO₂ to energy chemicals in aqueous electrolytes is usually limited by logy OER at the anode and competing HER at the cathode. An N-doped carbon encapsulated Cu–CoO composite (CuCo@NC) fabricated by the facile pyrolysis of Cu and Co salts and melamine mixture was used as a cathode for CO₂ reduction to CO and CH₄, coupled with the anodic oxidation of CH₃OH to dimethoxymethane in an ionic liquid-methanol medium to boost the anode reaction. The electrolytic system exhibits efficient redox activity with a higher average FE_DMM (58.7%) within 48 h and high instantaneous FE_C1 (99.1%) for CO + CH₄ at 24 h. Simultaneous production of the high-value chemicals DMM and CO + CH₄ in an electrolysis cell is achieved. The surface composition and structure of this composite with higher saturation magnetization, specifically the contribution of the Cu, CuO_x, and CoO_x crystallines to the catalytic performance of CO₂eRR and magnetic properties, were explored. The catalytic system achieves high activity within 72 h of continuous electrolysis, and the electrode and ionic liquid can remain intact after being used three times, indicating the high operational stability of the CO₂eRR system.