Electrocatalytic nitrite reduction to ammonia on isolated bismuth alloyed ruthenium

Electrochemical reduction of NO₂⁻ to NH₃ (NO₂⁻RR) is recognized as an appealing approach for achieving renewable NH₃ synthesis and waste NO₂⁻ removal. Herein, we report isolated Bi alloyed Ru (Bi₁Ru) as an efficient NO₂⁻RR catalyst. Theoretical calculations and in situ electrochemical measurements reveal the creation of Bi₁-Ru dual sites which can remarkably promote NO₂⁻ activation and suppress proton adsorption, while accelerating the NO₂⁻RR protonation energetics to render a high NO₂⁻-to-NH₃ conversion efficiency. Remarkably, Bi₁Ru assembled in a flow cell delivers an NH₃ yield rate of 1901.4 μmol h⁻¹ cm⁻² and an NH₃-Faradaic efficiency of 94.3% at an industrial-level current density of 324.3 mA cm⁻². This study offers new perspectives for designing and constructing p-block single-atom alloys as robust and high-current-density NO₂⁻RR catalysts toward the ammonia electrosynthesis.