The idea of single-atom catalysts (SACs) has gained attention in electrocatalysis owing to its high efficiencies in energy conversion reactions. Supported single-atoms (SAs) exhibit major advantages, such as high atom utilization, strong interfacial interaction, and well-defined active centers, compared with nanoparticles. From a practical point of view, SACs comprising non-noble metals seem to be an attractive alternative to expensive noble-metal catalytic systems. As the intrinsic activity and the electronic structure of SACs are governed by the support material and coordination environment of the metal species. Two-dimensional (2D) materials could be a promising candidates for supporting SAs owing to their high chemical stabilities and layered structures. This review provides an overview of recent developments in 2D materials-supported non-noble metal SACs for electrochemical energy conversion applications. The relevance of performing the comprehensive characterization of the 2D supported catalysts to elucidate their catalytic activities under different reaction conditions were highlighted. In light of recent findings in the field, we discussed the existing challenges and future opportunities regarding the correlation between the 2D structures and activities of SACs toward electrochemical energy conversion reactions.

单原子催化剂（SACs）的想法由于其在能量转换反应中的高效率而在电催化中受到关注。与纳米粒子相比，受支持的单原子（SAs）具有原子利用率高、界面相互作用强、活性中心明确等主要优点。从实用的角度来看，包含非贵金属的 SAC 似乎是昂贵的贵金属催化系统的有吸引力的替代品。由于 SACs 的内在活性和电子结构受金属物质的载体材料和配位环境的支配。二维（2D）材料由于其高化学稳定性和层状结构，可能是支持 SA 的有希望的候选材料。本综述概述了用于电化学能量转换应用的二维材料支持的非贵金属 SAC 的最新进展。强调了对二维负载催化剂进行综合表征以阐明其在不同反应条件下的催化活性的相关性。鉴于该领域的最新发现，我们讨论了关于二维结构与 SAC 活性与电化学能量转换反应之间的相关性的现有挑战和未来机遇。