Recent decades have witnessed the rapid development of catalytic science, especially after Taylor and Armstrong proposed the notion of the “active site” in 1925. By optimizing reaction paths and reducing the activation energies of reactions, catalysts appear in more than 90% of chemical production reactions, involving homogeneous catalysis, heterogeneous catalysis, and enzyme catalysis. Because of the 100% efficiency of active atom utilization and the adjustable microenvironment of metal centers, single-atom catalysts (SACs) shine in various catalytic fields for enhancing the rate, conversion, and selectivity of chemical reactions. Nevertheless, a solo active site determines a fixed adsorption mode, and the adsorption energies of intermediates from multistep reactions linking with a solo metal site are related to each other. For a specific multistep reaction, it is almost impossible to optimally adjust the adsorption of every intermediate on the solo site simultaneously. This phenomenon is termed the scaling relationship limit (SRL) and is an unavoidable obstacle in the development of pure SACs.

中文翻译：

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打破尺度关系限制：从单原子催化剂到双原子催化剂

近几十年见证了催化科学的快速发展，特别是在 1925 年 Taylor 和 Armstrong 提出“活性位点”的概念之后。通过优化反应路径和降低反应的活化能，催化剂出现在 90% 以上的化工生产中反应包括均相催化、多相催化和酶催化。由于活性原子的 100% 利用率和金属中心的可调节微环境，单原子催化剂 (SACs) 在提高化学反应的速率、转化率和选择性方面在各个催化领域大放异彩。然而，单独的活性位点决定了固定的吸附模式，与单独的金属位点连接的多步反应中间体的吸附能是相互关联的。对于特定的多步反应，几乎不可能同时优化调整每个中间体在单独位点上的吸附。这种现象被称为比例关系限制（SRL），是纯 SAC 开发中不可避免的障碍。