Dual Active Centers Bridged by Oxygen Vacancies of Ruthenium Single‐Atom Hybrids Supported on Molybdenum Oxide for Photocatalytic Ammonia Synthesis

Abstract

Photocatalytic synthesis of ammonia (NH₃ ) holds significant potential compared with the Haber-Bosch process. However, the reported photocatalysts suffer from low efficiency owing to localized electron deficiency. Herein, Ru-SA (single atoms)/H_x MoO_3-y hybrids with abundant of Moⁿ⁺ (4<n<6) species neighboring oxygen vacancies (O_V ) are synthesized via a H-spillover process. Detailed characterizations demonstrate that Ru-SA/H_x MoO_3-y hybrids can quantitatively produce NH₃ from N₂ and H₂ through the presence of dual active centers (Ru SA and Moⁿ⁺ ). The Ru SA boost the activation and migration of H₂ , and Moⁿ⁺ species act as the trapping sites of localized electrons and the adsorption and dissociation sites of N₂ , finally leading to NH₃ synthesis on Moⁿ⁺ -OH. The NH₃ generation rate is up to 4.0 mmol h^-1 g^-1 , accompanied by an apparent quantum efficiency over 6.0 % at 650 nm.