Heterogeneous catalysts have made outstanding advancements in pollutants elimination as well as energy and materials production over the past decades. Single-atom alloys (SAAs) are novel environmental catalysts prepared by dispersing single metal atoms on other metals. Integrating the advantages of single atom and alloys, SAAs can maximize atom utilization, reduce the use of noble metals and enhance catalytic performances. The synergistic, electronic and geometric effects of SAAs are effective to modulate the activation energy and adsorption strength, consequently breaking linear scaling relationship as well as offering an excellent catalytic activity and selectivity. Moreover, SAAs possess clear atomic structure, active sites and reaction mechanisms, providing an opportunity to tailor catalytic properties and develop effective environmental catalysts. In this review, we provide the recent progress on synthetic strategies, catalytic properties and catalyst design of SAAs. Furthermore, the applications of SAAs in environmental catalysis are introduced towards catalytic conversion and elimination of different air pollutants in many important reactions including (electrochemical) oxidation of volatile organic compounds (VOCs), dehydrogenation of VOCs, CO₂ conversion, NO_x reduction, CO oxidation, SO₃ decomposition, etc. Finally, challenges and opportunities of SAAs in a broad environmental field are proposed.

在过去的几十年里，多相催化剂在污染物消除以及能源和材料生产方面取得了显着进步。单原子合金（SAA）是通过将单个金属原子分散在其他金属上制备的新型环境催化剂。SAA综合了单原子和合金的优点，可以最大限度地提高原子利用率，减少贵金属的使用，提高催化性能。SAA 的协同效应、电子效应和几何效应可有效调节活化能和吸附强度，从而打破线性比例关系并提供优异的催化活性和选择性。此外，SAA 具有清晰的原子结构、活性位点和反应机制，为定制催化性能和开发有效的环境催化剂提供了机会。在这篇综述中，我们提供了 SAA 合成策略、催化性能和催化剂设计的最新进展。此外，SAA在环境催化中的应用被引入到催化转化和消除许多重要反应中的不同空气污染物，包括挥发性有机化合物（VOCs）的（电化学）氧化，VOCs的脱氢，CO₂转化、NO _x还原、CO 氧化、SO ₃分解等。最后，提出了SAA 在广泛的环境领域中的挑战和机遇。