Electrochemical CO₂ Reduction Using Copper-Zinc and Copper-Bismuth Catalysts: Mechanistic Insights and Design...

The electrochemical reduction of CO₂ (ECO₂RR) has emerged as a promising route for converting CO₂ into value-added chemicals and fuels using renewable electricity. Among transition metals, copper uniquely enables the formation of C₁ and C₂ products, but it suffers from poor selectivity and stability in its monometallic form. This review explores recent advances in Cu-Zn and Cu-Bi bimetallic systems, emphasizing how their structural, electronic, and interfacial characteristics influence ECO₂RR pathways and product distribution. Mechanistic insights into active site behavior, alloying effects, and the role of surface facets are provided. Limitations such as catalyst degradation and scalability are critically discussed, including a comparing performance across different electrochemical cell configurations. Finally, design guidelines and future research directions are proposed to enhance Cu-based bimetallic catalysts' selectivity, stability, and scalability for ECO₂RR.