Developing highly efficient electrocatalysts with low cost is critical for the wide‐spread application of sustainable and renewable energy conversion technologies. Single‐atom catalysts (SACs) have attracted considerable attention owing to their high catalytic activity, selectivity, and stability. However, the high surface energy of the single atoms often results in an extremely low loading of metal atom catalysts with limited mass activity. In this context, densely populated SACs are more promising for practical applications due to their high active surface area and mass activity. Herein, the recent research progress of high loading (≥5 wt%) SACs for different electrocatalytic applications is summarized. An overview of various synthesis and characterization strategies of SACs is presented in this review. The influence of appropriate substrates on the preparation of high metal loading SACs is also discussed. In addition, this review provides valuable insights into the current challenges and future opportunities in the field of single‐atom catalysts.

中文翻译：

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人口稠密的单原子催化剂

开发低成本的高效电催化剂对于可持续和可再生能源转换技术的广泛应用至关重要。单原子催化剂（SAC）由于具有高催化活性，选择性和稳定性而备受关注。但是，单个原子的高表面能通常会导致具有极低质量活性的金属原子催化剂的负载极低。在这种情况下，人口稠密的SAC具有较高的活性表面积和质量活性，因此在实际应用中更具前景。在此，总结了高载量（≥5wt％）SAC在不同电催化应用中的最新研究进展。本文综述了SAC的各种合成和表征策略。还讨论了合适的基材对高金属负载SAC制备的影响。此外，本综述提供了有关单原子催化剂领域当前挑战和未来机遇的宝贵见解。