Understanding the microenvironment structure‐activity relationship of singlet‐atom catalysts (SACs) is imperative for the development of high‐performance photocatalytic devices. However, the challenge remains to finely regulate the coordination microenvironment of SACs. Herein, single‐atom Nx─Cu─O4‐x (x = 1–4) photocatalysts with different coordination environments are successfully prepared based on pre‐design reticular supramolecular covalent organic frameworks (COFs) for direct photocatalytic 1O2 production from O2. The results show that the high activity of Cu SACs is closely related to the N,O‐coordination microenvironment, which is primarily ascribed to the different electrophilicity of the N, O atom. The electron configuration of N3‐Cu‐O1 endows photocatalyst enhanced charge transfer capability and the nearest D‐band center to the Fermi level. The “end‐on” type adsorption configuration of O2 at the N3─Cu─O1 active site can promote the breaking of Cu─O bonds rather than O─O bonds. As a result, the N3‐Cu‐O1@COF photocatalyst exhibits the most optimal formation and desorption energies for intermediates •OOH, which provides an advantageous reaction pathway with fewer steps and a lower barrier for 1O2 production. This work highlights the structure‐activity relationship of SACs for long‐term applications.

中文翻译：

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通过不饱和N,O-配位阐明用于单线态氧生产的Cu单中心催化剂的微环境构效关系


了解单线态原子催化剂（SAC）的微环境构效关系对于开发高性能光催化器件至关重要。然而，精细调控 SAC 的协调微环境仍然是一个挑战。在此，基于预先设计的网状超分子共价有机框架（COF），成功制备了具有不同配位环境的单原子Nx─Cu─O4-x（x = 1-4）光催化剂，用于直接光催化从O2生产1O2。结果表明，Cu SACs的高活性与N，O配位微环境密切相关，这主要归因于N，O原子的不同亲电性。 N3-Cu-O1 的电子构型赋予光催化剂增强的电荷转移能力和最接近费米能级的 D 能带中心。 N3─Cu─O1活性位点上O2的“端上”型吸附构型可以促进Cu─O键的断裂，而不是O─O键的断裂。因此，N3-Cu-O1@COF光催化剂对中间体·OOH表现出最佳的形成和解吸能，这为1O2的生产提供了一条步骤更少、势垒更低的有利反应途径。这项工作强调了 SAC 的长期应用的构效关系。