Efficient nitric oxide electroreduction toward ambient ammonia synthesis catalyzed by a CoP nanoarray

Abstract

The ever-increasing anthropic NO emission from fossil fuel combustion has resulted in a series of severe environmental issues. Ambient electrocatalytic NO reduction has emerged as a promising route for sustainable NO abatement and energy-saving NH₃ synthesis, but it is kinetically complex and energetically challenging, thus requiring electrocatalysts with high activity and selectivity. Herein, we demonstrate the direct use of a CoP nanowire array on Ti mesh (CoP/TM) as an efficient hydroprocessing catalyst for electrochemically converting NO to NH₃. This monolithic catalyst achieves a faradaic efficiency of 88.3% and an NH₃ yield of 47.22 μmol h⁻¹ cm⁻², much superior to its Co(OH)F counterpart (30.3%, 4.21 μmol h⁻¹ cm⁻²). Significantly, it exhibits high durability and negligible activity decay for 14 h bulk electrolysis. The excellent electrocatalytic NO reduction activity of our CoP/TM is demonstrated further by using it as a Zn–NO battery cathode catalyst. Theoretical calculations reveal the catalytic mechanisms.