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

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)/HxMoO3-y hybrids with abundant of Mon+ (4<6) neighboring oxygen vacancies (O-v) are synthesized via a H-spillover process. Detailed characterizations demonstrate that Ru-SA/HxMoO3-y hybrids can quantitatively produce NH3 from N-2 and H-2 through the presence of dual active centers (Ru SA and Mon+). The Ru SA boost the activation and migration of H-2, and Mo(n+ )species act as the trapping sites of localized electrons and the adsorption and dissociation sites of N-2, 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.

Automated summary

In this study, Ru-SA/HxMoO3-y hybrids were synthesized and demonstrated to be efficient in photogenerated synthesis of NH3. The dual active centers (Ru SA and Mon+) play important roles in promoting the activation and migration of H-2 and the adsorption and dissociation of N-2, leading to high NH3 generation rate and quantum efficiency.