Melchionna Michele, Fornasiero Paolo
Department of Chemical and Pharmaceutical Sciences, Center for Energy, Environment and Transport Giacomo Ciamiciam, INSTM Trieste Research Unit and ICCOM-CNR Trieste Research Unit, University of Trieste, Via L. Giorgieri 134127Trieste, Italy.
J Am Chem Soc. 2025 Jan 22;147(3):2275-2290. doi: 10.1021/jacs.4c15803. Epub 2025 Jan 6.
Despite their enormous impact in modern heterogeneous catalysis, single-atom catalysts (SACs) continue to puzzle the catalysis community, which often struggles to draw correct conclusions in SAC-catalyzed experiments. In many cases, the reasons for such an uncertainty originate from the lack of knowledge of the exact single-atom evolution under operative conditions and the fundamental factors controlling the fate of the single atom in relation to the catalytic mechanism. This has led to confusion also about correct definition and terminology, where the coined term reflects the difficulty in defining the true active species as well as in obtaining long-range ordered homogeneous supports [Chi, S.; et al. , , 49-57. DOI: 10.1016/j.jcat.2023.02.003]. Most recent studies have attempted to clarify several of the key aspects that are in play during SAC catalysis. However, one largely overlooked opportunity is to take advantage of all the dynamic phenomena occurring at the single metal site to turn the conventional catalytic sequences into a smart, stimulus-responsive, and controllable evolution of the single atom under operative conditions. Such "smartness" could potentially unleash pathways that mitigate some of the typical drawbacks of SACs, such as selectivity and stability. Here we present our vision on these yet-unexplored opportunities for exploiting the dynamicity of SACs, and we discuss various examples that could be the cornerstones for the advent of a next generation of SACs, that we term here "smart" single-atom catalysts (SSACs). Despite smart-behaving SACs still being far from realization, the clues provided here suggest pathways to achieve this goal.
尽管单原子催化剂（SACs）在现代多相催化中具有巨大影响，但它们仍令催化领域感到困惑，催化领域在SAC催化实验中常常难以得出正确结论。在许多情况下，这种不确定性的原因源于对实际操作条件下精确的单原子演化缺乏了解，以及缺乏控制单原子命运与催化机制相关的基本因素的知识。这也导致了在正确定义和术语方面的混乱，其中新造的术语反映了定义真正活性物种以及获得长程有序均匀载体的困难[Chi, S.等人，《催化杂志》，2023年，第49 - 57页。DOI: 10.1016/j.jcat.2023.02.003]。最近的研究试图阐明SAC催化过程中起作用的几个关键方面。然而，一个很大程度上被忽视的机会是利用在单个金属位点发生的所有动态现象，将传统的催化序列转变为在实际操作条件下单原子的智能、刺激响应和可控演化。这种“智能性”有可能释放出减轻SACs一些典型缺点（如选择性和稳定性）的途径。在这里，我们展示了关于利用SACs动态性的这些尚未探索的机会的愿景，并讨论了各种可能成为下一代SACs（我们在此称之为“智能”单原子催化剂（SSACs））出现基石的例子。尽管表现出智能的SACs仍远未实现，但这里提供的线索表明了实现这一目标的途径。
