Single-atom catalysts (SACs) have gained widespread popularity in heterogeneous catalysis-based advanced oxidation processes (AOPs), owing to their optimal metal atom utilization efficiency and excellent recyclability by triggering reactive oxidative species (ROS) for target pollutant oxidation in water. Systematic summaries regarding the correlation between the active sites, catalytic activity, and reactive species of SACs have rarely been reported. This review provides an overview of the catalytic performance of carbon- and metal oxide-supported SACs in Fenton-like reactions, as well as the different oxidation pathways induced by the metal and non-metal active sites, including radical-based pathways (e.g., ·OH and SO₄˙⁻) and nonradical-based pathways (e.g. ¹O₂, high-valent metal-oxo species, and direct electron transfer). Thereafter, we discuss the effects of metal types, coordination environments, and spin states on the overall catalytic performance and the generated ROS in Fenton-like reactions. Additionally, we provide a perspective on the future challenges and prospects for SACs in water purification.

中文翻译：

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单原子催化类芬顿反应中活性位点和氧化物质的关联


单原子催化剂（SAC）因其最佳的金属原子利用效率和通过触发活性氧化物质（ROS）氧化水中目标污染物而具有优异的可回收性，在基于多相催化的高级氧化过程（AOP）中获得了广泛的应用。关于 SAC 的活性位点、催化活性和反应物种之间的相关性的系统总结很少有报道。本综述概述了碳和金属氧化物负载的 SAC 在类芬顿反应中的催化性能，以及金属和非金属活性位点诱导的不同氧化途径，包括基于自由基的途径（例如， ·OH 和 SO ₄ ˙ ⁻ ）和非自由基途径（例如 ¹ O ₂ ，高价金属氧物种，以及直接电子转移）。此后，我们讨论了金属类型、配位环境和自旋态对类芬顿反应中整体催化性能和生成的 ROS 的影响。此外，我们还对 SAC 在水净化领域的未来挑战和前景提出了看法。