Facing serious environmental pressures from industrial CO2 emissions, adopting solar energy, an abundant, carbon-free resource, as a substitute for fossil-derived heat and electrons is a promising decarbonization pathway. The limited efficiency of reactant adsorption and activation continues to hinder photocatalytic performance. By offering atomically dispersed active sites, SACs present a feasible pathway to mitigate these bottlenecks.

In this dissertation, SACs were developed and applied to a series of representative industrial chemical transformations. EXAFS and aberration-corrected HAADF-STEM were employed to confirm the presence of isolated metal centers, while in situ EPR and in situ DRIFTS were performed to track the key intermediates and clarify how the optimized catalytic architecture influence the reaction mechanism. Photoexcited carriers was captured and concentrated at single-atom sites, strengthening reactant activation and thus lowering kinetic barriers, and the uniform, well-defined coordination environment resulted a single, predictable adsorption mode, yielding a consistent transformation pathway.

Consequently, compared with the conventional industrial process, the optimized systems achieve high product formation rates and selectivity at reduced operating temperatures, substantially decreasing fossil-energy demand and associated CO2 emissions. In the final stage of research, outdoor trials under natural sunlight were performed and delivered stable production of H2 and pyruvic acid; the persistence of activity and selectivity under fluctuating irradiance and ambient conditions underscores the robustness, scalability, and real-world application potential of these solar-driven catalytic systems.