Coordination regulation of single-atom catalysts toward enhanced photocatalytic ammonia synthesis

Abstract

Photocatalytic ammonia synthesis is a sustainable pathway to substitute the Haber–Bosch reaction where high energy consumption exists, and single-atom catalysts (SACs) are pivotal materials in this field that rely on their maximized atom utilization rate and tunable local electronic structure. This review systematically summarizes recent advances in single-atom regulation for enhanced photocatalytic ammonia synthesis. First, SACs are categorized by atomic type, elucidating distinct roles played by different single-atom loadings in modulating catalytic performance. Second, precise active-site regulation strategies are delineated through a tripartite framework: coordination environment engineering, spatial site positioning, and support interface engineering. Subsequently, the breakthrough progress in the photocatalytic ammonia synthesis efficiency of SACs is critically examined, focusing on structure-property correlations. Finally, we discuss the pivotal role played by in situ characterization techniques (e.g., FTIR, Raman, XPS, XAFS) in unveiling reaction mechanisms and dynamic structural evolution. This work offers foundational theoretical guidance for rational design paradigms of high-efficiency SACs photocatalysts applied in regulated photocatalytic ammonia synthesis.