Long‐Range Coordination Environment Modulates Single‐Atom Local States and Systemic Impact on CO ₂ Photoconversion

Catalytic performance of single‐atom catalysts (SACs) is highly dependent on their local coordination structures. However, conventional synthesis methods struggle to achieve precise design and systematic control of active sites. Herein, this study proposes using Cu porphyrins modified with a terminal group as pre‐set active centers. Through molecular engineering strategies, their electronic structures are pre‐regulated for controlled assembly into high‐performance hybrid photocatalysts. Using structurally defined Cu porphyrins as a model system, the long‐range electronic effects of ─COOH, ─CN, and ─NO 2 terminal groups on the central Cu atom are systematically investigated, revealing their remote perturbation of the local electronic state without altering the Cu coordination geometry. By assembling customized molecular sites with supports, a multidimensional descriptor framework is established to evaluate the cascading influence of terminal‐group regulation from local active sites to the CO 2 photoreduction performance. Cross‐scale correlations among terminal groups, Cu electronic structures, interfacial charge behavior, and catalytic performance are thereby constructed, enabling an outside‐in electronic regulation strategy for pre‐designed single‑atom photocatalysts. This study provides new perspectives and a theoretical foundation for rational design of high‐performance single‐atom photocatalysts via long‑range electronic modulation of active sites.