A joint strategy for CO2 reduction and CH3OH oxidation at electrode to CO + CH4 and methylal in ionic liquid

Abstract

Electrochemical reduction reaction of CO2 (CO2eRR) in aqueous electrolyte currently encounters with sluggish oxygen evolution at anode and hydrogen evolution as a competing reaction at cathode. A Cu-FeOx-N-doped carbon composite (CFCN) prepared by facile pyrolysis of Cu-Fe salts and melamine was used as cathode, associated with Pt sheet anode to perform CO2eRR to CO + CH4 and partial oxidation of methanol to methylal (DMM) in ionic liquid-methanol electrolyte solution. The electrolysis exhibits efficient red-ox activity with higher average FEDMM (59.9%) for DMM within 24 h and high momentary FEC1 (87.2%) for CO + CH4 at 24 h, specifically, realizing red-ox reactions couple for synchronously producing high-valued chemicals, DMM and CO + CH4. Besides, the composite also demonstrates high saturation magnetization (110 emu/g). The catalytic role and contribution of the various components such as metal Cu, CuOx and Fe3O4 nanocrystallines constituting the composite for CO2eRR and to magnetic property were examined. The catalyst possesses high run stability for CO2eRR as the electrolysis has continuously performed for 120 h.

Keywords

• CO2 reduction
• Electrocatalysis
• Dimethoxymethane
• Ionic liquid electrolyte
• Methane