Multi-metallic catalysts for the electroreduction of carbon dioxide: Recent advances and perspectives

Electrochemical CO2 reduction reaction (ECO2RR) offers an opportunity to sustainably convert CO2 into value-added fuels and chemicals by using the electricity that could be generated by renewable energies. Recently, enormous efforts are focused on the development of metal-based catalysts for the selective ECO2RR with high efficiency. Multi-metallic catalyst design emerges as one of the most promising strategies for the promotion of the Faradaic efficiency (FE), the current density, and the lowering of the overpotential of the catalysts for ECO2RR. The synergistic effects of the different metal sites in the hybrid catalysts are of significance for the enhancement of the ECO2RR performance. This review summarizes the rational design of multi-metallic catalysts, including alloy, atomically dispersed multi-metallic sites, and others, along with the popular metal elements studied in multi-metallic catalysts to clarify the advantages of different metal elements for ECO2RR. The density functional theory (DFT) simulations and advanced in-situ characterizations that contribute to demystifying the synergies between metal elements are highlighted. Challenges and outlook concerning the catalyst design and reaction mechanism of multi-metallic catalysts for ECO2RR are also discussed.