Pd1Cu Single-Atom Alloys for High-Current-Density and Durable NO-to-NH3 Electroreduction

Electrochemical reduction of NO to NH3 (NORR) offers a prospective method for efficient NH3 electrosynthesis. Herein, we first design single-atom Pd-alloyed Cu (Pd1Cu) as an efficient and robust NORR catalyst at industrial-level current densities (>0.2 A cm–2). Operando spectroscopic characterizations and theoretical computations unveil that Pd1 strongly electronically couples its adjacent two Cu atoms (Pd1Cu2) to enhance the NO activation while promoting the NO-to-NH3 protonation energetics and suppressing the competitive hydrogen evolution. Consequently, the flow cell assembled with Pd1Cu exhibits an unprecedented NH3 yield rate of 1341.3 μmol h–1 cm–2 and NH3–Faradaic efficiency of 85.5% at an industrial-level current density of 210.3 mA cm–2, together with an excellent long-term durability for 200 h of electrolysis, representing one of the highest NORR performances on record.