Transition Metals Based Dual Single-atom Catalysts for Oxygen Electrocatalysis: Stunning Advances and Future Prospects

During the past few years, single-atom catalysts (SACs) have attracted considerable attention in electrolysis due to their outstanding catalytic performance and efficient atomic utilization. SACs exhibit a simple structure, high catalytic activity, consistent scaling relationships for single sites, and low metal content but their practical applications are still limited. Dual single-atom catalysts (DACs), which feature excellent selectivity, high atomic utilization efficiency, and remarkable stability, are emerging as new frontiers in heterogeneous electrocatalysis. They increase catalytic activity by promoting synergistic effects between metal-active sites. In this paper, we present a comprehensive overview of the latest developments in dual-atom catalysts for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). In addition, we explore the differences between homonuclear and heteronuclear configurations, the emergence of single/dual-site metal catalysts, and the methods currently used for their synthesis. Lastly, this review discusses several perspectives for advancing the development of dual-atom catalysts for OER and ORR electrocatalysis. Dual/single atom catalysts (DACs) modify single-metal centers to create functionalized catalysts with greater rationality. By introducing secondary metal atoms to the surface of catalytic centers, DACs provide an attractive material space with intriguing surface chemistry, effectively enhancing the electrocatalytic performance of oxygen catalysis and long-term stability due to their flexible active site configuration and higher metal content. This review provides a detailed discussion of a variety of fabrication methods for dual/single atom-based electrocatalysts, and how different features of the DACs communicate with oxygen catalysis.+ image