Cuo Doping Sio2 for Enhancing Electron Transfer to Product C2h4 in Electrocatalytic Co2 Reduction

Abstract

Electrocatalytic CO2 reduction reaction (CO2RR) offers an effective strategy to mitigate excessive carbon emissions. The reaction mechanism of CO2RR is intricate, yielding a wide variety of products, with ethylene (C2H4) being one of the crucial products. However, due to the inherent inertness of CO2 and the significant thermodynamic barriers at ambient temperature and pressure, achieving efficient electrochemical reduction of CO2 to C2H4 remains a formidable challenge. One promising solution involves the development of CuO-based electrocatalysts to enhance the Faradaic efficiency for C2H4 production.Silicon dioxide (SiO2) is widely employed as a dopant in catalysis, owing to its versatile properties. In this study, SiO2 was doped into CuO to achieve efficient CO2 conversion. The resulting SiO2-doped CuO catalysts demonstrated a maximum Faradaic efficiency of 42% for C2H4 at a potential of -1.4 V (vs. RHE) with a partial current density of 6.3 mA/cm², which is over three times higher than that of the pure CuO catalyst.Characterization results indicate that the improved catalytic performance of CuO can be attributed to the incorporation of SiO2. The synergistic effect between SiO2 and CuO enhanced the electrochemically active surface area, improved reaction kinetics, accelerated charge transfer, and increased selectivity towards C2H4 production. Additionally, the SiO2-10%/CuO catalyst exhibited remarkable long-term stability, consistently maintaining a Faradaic efficiency for C2H4 above 40% at -1.4 V (vs. RHE) over extended periods.This work provides a novel strategy for designing electrocatalysts to promote the electrochemical reduction of CO2 to C2H4.

Keywords: CO2RR, Electrocatalysts, CuO, SiO2, Synergistic effect