p-Block Antimony Single-Atom Catalysts for Nitric Oxide Electroreduction to Ammonia

Electrocatalytic NO reduction to NH₃ (NORR) offers a prospective approach to attain both harmful NO removal and efficient NH₃ electrosynthesis. Main-group p-block metals are promising NORR candidates but still lack adequate exploration. Herein, p-block Sb single atoms confined in amorphous MoO₃ (Sb₁/a-MoO₃) are designed as an efficient NORR catalyst, exhibiting the highest NH₃ yield rate of 273.5 μmol h^-1 cm^-2 and a NO-to-NH₃ Faradaic efficiency of 91.7% at −0.6 V vs RHE. In situ spectroscopic characterizations and theoretical computations reason that the outstanding NORR performance of Sb₁/a-MoO₃ arises from the isolated Sb₁ sites, which can optimize the adsorption of *NO/*NHO to lower the reaction energy barriers and simultaneously exhibit a higher affinity to NO than to H₂O/H species. Moreover, our strategy can be extended to prepare Bi₁/a-MoO₃, showing a high NORR property, demonstrating the immense potential of p-block metal single-atom catalysts toward the high-performing NORR electrocatalysis.