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

Electrochemical reduction of NO to NH 3 (NORR) offers a prospective method for efficient NH 3 electrosynthesis. Herein, we first design single-atom Pd-alloyed Cu (Pd 1 Cu) 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 Pd 1 strongly electronically couples its adjacent two Cu atoms (Pd 1 Cu 2 ) to enhance the NO activation while promoting the NO-to-NH 3 protonation energetics and suppressing the competitive hydrogen evolution. Consequently, the flow cell assembled with Pd 1 Cu exhibits an unprecedented NH 3 yield rate of 1341.3 μmol h –1 cm –2 and NH 3 –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.