Single-atom catalysts (SACs) have obtained a great deal of attention in many catalytic fields due to the high atom utilization efficiency and high catalytic activity. Recently, great achievements on SACs have been made for thermocatalysis, electrocatalysis, and photocatalysis which play an important role in obtaining value-added products. However, it remains a great challenge to fabricate SACs with high metal loading and investigate their reaction mechanisms. Therefore, it is necessary to highlight the recent development of SACs in these fields to guide future research. In this review, we overviewed the thermocatalysis applications of SACs in CO oxidation, preferential oxidation of CO, water-gas shift reaction, methane conversion, methanol steam reforming, aqueous-phase reforming of methanol, hydrogenation of alkynes and dienes, hydrogenation of CO, and hydrogenation of substituted nitroarenes. Moreover, the oxygen reduction reaction (ORR), hydrogen evolution reaction (HER), oxygen evolution reaction (OER), CO 2 reduction reaction (CO 2 RR), and N 2 reduction reaction (N 2 RR) for photocatalytic and electrocatalytic fields were also overviewed. Lastly, the opportunities and challenges of SACs were pointed out.

中文翻译：

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单原子催化的最新进展

单原子催化剂（SACs）由于原子利用效率高、催化活性高而在许多催化领域受到广泛关注。近年来，SACs 在热催化、电催化和光催化方面取得了巨大成就，在获得高附加值产品方面发挥着重要作用。然而，制造具有高金属负载量的 SAC 并研究其反应机制仍然是一个巨大的挑战。因此，有必要强调 SACs 在这些领域的最新发展，以指导未来的研究。在这篇综述中，我们概述了 SAC 在 CO 氧化、CO 优先氧化、水煤气变换反应、甲烷转化、甲醇蒸汽重整、甲醇水相重整、炔烃和二烯加氢中的热催化应用，CO的加氢和取代硝基芳烃的加氢。此外，光催化和电催化领域的氧还原反应（ORR）、析氢反应（HER）、析氧反应（OER）、CO 2 还原反应（CO 2 RR）和N 2 还原反应（N 2 RR）也概述了。最后，指出了SACs的机遇和挑战。