Interactions between Graphene Nanosheets and Copper Oxide Promote C ₂ Formation in Rapid CO ₂ Electroreduction

High Resolution Image Download MS PowerPoint Slide Copper-based catalysts can electrochemically reduce carbon dioxide into valuable multicarbon products, offering a promising solution to mitigate atmospheric CO 2 levels. However, their practical application is hindered by limited product selectivity and an insufficient C 2 current density at high operating currents. To overcome these limitations, in this study, we develop graphene-supported copper oxide electrocatalysts aimed at enhancing the catalytic performance of the CO 2 reduction reaction (CO 2 RR) to C 2 products. This enhancement is attributed to strong electronic interactions between the copper d-orbitals and carbon species, together with improved electrical conductivity, as evidenced by soft X-ray absorption spectroscopy and electrochemical impedance spectroscopy. The resulting electrocatalyst achieves a Faradaic efficiency of 70.45% for C 2 products at 400 mA/cm 2, with a partial current density of 281.8 mA/cm 2 . This performance markedly surpasses that of the benchmark copper electrocatalyst, which exhibits a comparable Faradaic efficiency of 70.27% only at 200 mA/cm 2, with a partial current density of 140.54 mA/cm 2 . Operando X-ray absorption spectroscopy reveals that CuO is rapidly reduced to a metallic state under reaction conditions, resembling the metallic copper benchmark; however, the interfacial interaction between copper and carbon enriches crucial reaction intermediates during the CO 2 RR, as evidenced by Operando Raman spectroscopy, in good agreement with the observed electrochemical product distribution. These findings provide valuable insights for the design of CO 2 RR electrocatalysts and contribute to the advancement of Net Zero emissions.