Synergies Between Atomically Dispersed Ru Single Atoms and Nanoparticles on CeAlOx for Enhanced Photo‐Thermal Catalytic CO ₂ Hydrogenation

Abstract Heterogeneous catalysts integrating single‐atom species and nanoparticles maximize atom utilization and hydrogen dissociation for hydrogenation reactions. However, challenges in maintaining consistent metal loadings during synthesis complicate direct performance comparisons with the single‐atom and nanoparticle‐based systems, which obscures rational assessment of their catalytic potential. Herein, Ru _1+NPs /CeAlO _x photothermal catalysts are reported which leverage the synergy between Ru single atoms and Ru nanoparticles to enhance CO ₂ hydrogenation to CH ₄ . Under light irradiation (3.1 W cm ⁻² , 200–1100 nm) at 200 °C, the Ru _1+NPs /CeAlO _x catalyst achieves a CH ₄ production rate of 197.2 mmol g _cat ⁻¹ h ⁻¹ with near‐100% selectivity, surpassing single‐atom Ru ₁ /CeAlO _x catalysts and nanoparticle‐based Ru _NPs /CeAlO _x catalysts, with equivalent metal contents. Mechanistic studies revealed that in Ru _1+NPs /CeAlO _x catalysts, Ru single atoms facilitate CO ₂ adsorption/activation and subsequent conversion, while Ru nanoparticles promote H ₂ dissociation, with their synergistic interplay driving superior performance. Moreover, the CeAlO _x support effectively stabilizes the dual‐site structure and facilitates the formation of reaction intermediates through its abundant oxygen vacancies and surface Lewis acid‐base pairs, thereby further enhancing the catalytic reaction. This work highlights the critical role of synergistic effects between single atoms and nanoparticles, offering new approaches for designing high‐efficiency hydrogenation catalysts.