Coupling Ru single-atom and oxygen vacancy in Ru/SnO2−x for efficient nitrogen reduction to ammonia via electronic synergistic effect

The electrochemical nitrogen reduction reaction (ENRR) is a promising approach for ammonia synthesis under ambient conditions, which presents considerable advantages over conventional synthesis methods. However, highly efficient catalysts are crucial to drive the ENRR reaction. Here, we developed a Ru/SnO2−x catalyst by depositing single-atomic Ru onto an oxygen vacancy (VO)-enriched SnO2 substrate. Theoretical calculations revealed intrinsic electronic synergy between VO and Ru, significantly reducing the energy barrier for the ENRR rate-determining step. Moreover, VO enhances conductivity and charge transfer efficiency. Our catalyst yielded an impressive 32.4 μg h−1 mgcat.−1 of ammonia, with a Faraday efficiency of 16.2 % and excellent electrochemical stability, surpassing most previously reported Ru-based ENRR catalysts.