Surface Modification of Nano-Cu₂ O for Controlling CO₂ Electrochemical Reduction to Ethylene and Syngas

In the surroundings of carbon neutrality, nano-Cu₂ O is considered a promising catalyst for the electrochemical CO₂ reduction reaction (ECO₂ RR), whose improvements in product selectivity still require considerable efforts. Here, we present an efficient strategy for controlling the ECO₂ RR product by modifying the surface of nano-Cu₂ O, i.e., by controlling the exposed facets via a reductant-controlled method to achieve the highest C₂ H₄ selectivity (Faradic efficiency=74.1 %) for Cu₂ O-based catalysts in neutral electrolytes, and introducing a well-suited metal-organic framework (MOF) coating on the surface of nano-Cu₂ O to obtain syngas completely with an appropriate H₂ :CO ratio. Detailed mechanism and key intermediate have been illustrated by DFT calculations. Our systematic strategy is expected to control the ECO₂ RR product, improve the selectivity, and provide a reliable method for CO₂ management and the green production of important carbon resources.