Advancing CO₂ conversion: the role of multi-metallic catalysts in CO₂ electroreduction

The rising global energy demand has accelerated fossil fuel consumption, leading to an increase in CO₂ emissions, the primary cause of the greenhouse effect. The CO₂ electroreduction reaction (CO₂RR) offers a green, sustainable solution to convert CO₂ into valuable chemicals and energy, which is crucial for achieving carbon neutrality. However, the CO₂RR faces significant hurdles, including its complex reaction pathways, low selectivity (due to CO₂'s stability and diverse products), competition with the hydrogen evolution reaction (HER) at high overpotentials, and challenges with catalyst stability and mass transport. To address these issues, multi-metallic catalysts consisting of two or more metal components have emerged as a highly promising strategy. Compared to monometallic catalysts, they offer enhanced selectivity through unique electronic regulation, optimized electronic structures, increased active sites, and reduced reliance on noble metals. This review summarizes recent advancements in multi-metallic catalysts, including alloy and dual-atom catalysts, and discusses microenvironment optimization strategies and the role of active sites. It also outlines future directions for catalyst development, aiming to guide research in this critical field.