Amorphous NiB2 for electroreduction of NO to NH3

Abstract

We explore amorphous NiB₂ as a metal diboride catalyst towards the efficient electroreduction of NO to NH₃ (NORR), showing the highest NH₃ yield rate of 167.1 μmol h⁻¹ cm⁻² and NH₃-faradaic efficiency (FE_NH3) of 89.6%. Theoretical calculations reveal that the Ni sites of NiB₂ serve as the main active centers that can not only optimize the binding energy of the key *NHO intermediate for reduced energy barriers, but also exhibit a stronger adsorption towards NO relative to H₂O/H species, thereby facilitating the active and selective NORR.