Abstract The development of low-cost and effective catalysts is highly necessary in the field of electrochemical applications. Recently, single atom and sub-nano catalysts (SACs and SNCs) have been emerging as excellent candidates due to their enriched active sites, extraordinary structural design, and unique electronic behavior. Therefore, the formation of well dispersed SACs and SNCs effectively stabilized on reasonable supports has been demonstrated as an advanced strategy to greatly improve the efficiency of catalytic processes. In addition, it also offered a wonderful opportunity to observe, study, and explain the mechanism of catalytic reactions at atomic scale. In this work, we comprehensively reviewed recent advances in state-of-the-art researches on the structures, properties, and applications of SACs and SNCs. The relationships between unique morphology/structures and intrinsic physicochemical properties of the catalysts were evaluated to further understand underlying reasons behind their advanced performance. Continuously, various potential electrochemical applications of SACs and SNCs were also emphasized in detail. Furthermore, some existing challenges in fundamental studies and practical applications, as well as forthcoming prospects for the development of SACs and SNCs were briefly discussed as well.

中文翻译：

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用于能源应用的单原子/亚纳米电催化剂的最新进展

摘要 在电化学应用领域，开发低成本、高效的催化剂是非常必要的。最近，单原子和亚纳米催化剂（SACs 和 SNCs）因其丰富的活性位点、非凡的结构设计和独特的电子行为而成为优秀的候选材料。因此，在合理的载体上形成有效稳定的分散良好的 SAC 和 SNC 已被证明是一种大大提高催化过程效率的先进策略。此外，它还提供了一个很好的机会，可以在原子尺度上观察、研究和解释催化反应的机理。在这项工作中，我们全面回顾了 SAC 和 SNC 的结构、性质和应用的最新研究进展。评估了催化剂的独特形态/结构与内在物理化学性质之间的关系，以进一步了解其先进性能背后的潜在原因。此外，还详细强调了 SAC 和 SNC 的各种潜在电化学应用。此外，还简要讨论了基础研究和实际应用中存在的一些挑战，以及 SAC 和 SNC 的发展前景。