Copper-based catalysts for CO2 electroreduction to C2/2+ products: Advance and perspective

[Display omitted] •The exploration of CO2 reduction reaction (CO2RR) over Cu-based electrocatalysts are highlighted.•A comprehensive discussion was provided on the reaction pathways of CO2RR toward C2/2+ products.•The “structure-performance relationship” of Cu-based catalysts was analyzed.•The impact from the electrode hydrophobicity and the electrolytes on CO2RR has also been discussed.•Challenges and perspectives associated with Cu-based catalysts were proposed. Electrocatalytic CO2 reduction reaction (CO2RR) is increasingly being recognized as an effective and promising technology to reutilize CO2 and convert it into high value-added products, which presents a viable pathway to actualize carbon neutrality. Owing to the distinct affinity of copper (Cu) to the key intermediates of CO2RR, Cu-based electrocatalysts are emerging as highly promising catalysts for producing multi-carbon (C2/2+) products through CO2RR. Notably, the deliberate design and advancement of Cu-based catalysts stand as pivotal factors in actualizing efficient and selective electrochemical reduction of CO2. In this review, we first elucidate the reaction pathways of Cu-based electrocatalysts for the synthesis of C2/2+ products. Then, various strategies toward the regulation of the structure of Cu-based catalysts are summarized, aiming to disclose the “structure-performance relationship”. Meanwhile, the important advances regarding the catalyst/electrolyte interface engineering as well as the electrolyte optimization toward improved C2/2+ production are also included. Lastly, the review concludes by critically summarizing both findings and perspectives and how this promising field might advance in the future.