Surface regulation of Cu-based catalysts to adjust the selectivity and promotion strategy of electrochemical reduction of CO₂ to C₂ products

Electrochemical CO₂ reduction reaction (CO₂RR) holds great promise as a method for converting CO₂ into valuable fuels and chemical raw materials using renewable energy. Cu, a key element in CO₂RR, has garnered significant attention for its ability to transform CO₂ into high-value fuels. In recent years, there has been a widespread focus on understanding various factors influencing the catalytic performance of copper, including crystal orientation, morphology, and size. Additionally, the presence of additive elements has been found to impact the reaction process through different mechanisms, influenced by concentration and binding forms. The catalytic design process is complicated by the intricate interplay of these factors, making it challenging to isolate individual effects. In this review, we examine the recent advancements in catalyst design, focusing on the influence of the surface structure of metallic Cu on the selectivity of CO₂RR. Additionally, we provide a summary of how additives contribute to enhancing catalyst performance. Novel concepts are put forth for the design of Cu-based catalysts, with the aim of overcoming the current selectivity challenges. To begin, we elucidate the impact of surface structure design on CO₂RR selectivity, with a specific emphasis on ethylene and ethanol production. Subsequently, we highlight the remarkable contributions of bimetallic catalysts to the selectivity of CO₂RR. Finally, we propose the incorporation of cooperative and confinement effects as a strategy to modulate the selectivity of CO₂RR. We look ahead to the future prospects of CO₂RR, anticipating further breakthroughs in this field.