Electrocatalytic nitrite reduction to ammonia on an Rh single-atom catalyst.

Electrocatalytic NO reduction to NH (NORR) holds great promise as a green method for high-efficiency NH production. Herein, an Rh single-atom catalyst where isolated Rh supported on defective BN nanosheets (Rh/BN) is reported to exhibit the exceptional NORR activity and selectivity. Extensive experimental and theoretical studies unveil that the high NORR performance of Rh/BN arises from the single-atom Rh sites, which not only promote the activation and hydrogenation of NO-to-NH process, but also hamper the undesired hydrogen evolution. Consequently, Rh/BN assembled in a flow cell exhibits the highest NH yield rate of 2165.4 μmol h cm and FE of 97.83 % at a high current density of 355.7 mA cm, ranking it the most efficient catalysts for NO-to-NH conversion.