Bimetallic effects in carbon dioxide electroreduction

As a clean and sustainable technology, electrocatalytic carbon dioxide reduction reaction (ECO₂RR) occupies a central position in the global energy transformation and climate change strategy. Compared with single metallic catalysts, bimetallic catalysts have many advantages, such as the synergistic effect between bimetals, enhanced CO₂ adsorption capacity, and lower reaction energy barriers, which make them widely used in the CO₂RR for the generation of multi-carbon products. This review systematically summarizes the latest advances in bimetallic effects for the CO₂RR. In this paper, we start with a classified introduction on the CO₂RR mechanisms, followed by a comprehensive discussion of the structure-activity relationships of various bimetallic catalysts, including regulation of metal centers, regulation of the distance between metal sites, regulation of the coordination environment, interface engineering, and strain engineering. Next, we showcase the advantages of bimetallic catalysts in the CO₂RR. Then, the research progress of typical bimetallic catalysts for the ECO₂RR is discussed, including diatomic catalysts, bimetallic alloys, bimetallic MOFs and bimetallic COFs. Finally, we summarize the challenges faced today from the five aspects of product selectivity, catalyst stability, product purification, theoretical simulations and in situ characterization techniques and put forward the research direction to promote the industrialization process of CO₂RR.