Single‐Atom Bi Alloyed Pd Metallene for Nitrate Electroreduction to Ammonia

Abstract

Abstract Electrochemical reduction of nitrate to ammonia (NO 3 RR) holds a great promise for attaining both NH 3 electrosynthesis and wastewater purification. Herein, single‐atom Bi alloyed Pd metallene (Bi 1 Pd) is reported as a highly effective NO 3 RR catalyst, showing a near 100% NH 3 ‐Faradaic efficiency with the corresponding NH 3 yield of 33.8 mg h −1 cm −2 at −0.6 V versus RHE, surpassing those of almost all ever reported NO 3 RR catalysts. In‐depth theoretical and operando spectroscopic investigations unveil that single‐atom Bi electronically couples with its neighboring Pd atoms to synergistically activate NO 3 − and destabilize *NO on Bi 1 Pd, leading to the reduced energy barrier of the potential‐determining step (*NO→*NOH) and enhanced protonation energetics of NO 3 − ‐to‐NH 3 pathway.