Dopant-site lattice turbulence of Cu-substituted Nb2O5 for efficient nitrogen electroreduction

Abstract

Lattice disorder engineering on highly crystalline texture toward high-efficiency N₂-to-NH₃ electrocatalysis is tremendously challenging. Here, abundant lattice disturbances were established on an ultrafine Nb₂O₅ nanoparticle by Cu substitution. Cu-Nb₂O₅ anchored on a carbon material (Cu-Nb₂O₅@C) exhibits excellent activity and high selectivity for N₂ electroreduction to NH₃ with a yield rate of 28.07 μg h⁻¹ mg⁻¹ and a faradaic efficiency (FE) of 13.25% at −0.2 V vs. reversible hydrogen electrode (RHE) in acidic electrolyte. Cu-Nb₂O₅@C presents superb durability with no obvious change in catalyst constituents and structure after N₂ reduction as confirmed by ex situ characterization studies. The excellent catalytical performance should originate from structural superiority of lattice turbulence for more active sites and optimized electronic state as well as good conductivity of carbon support. Meanwhile, in neutral electrolyte, the NH₃ FE also reaches up to 10.29% at the same potential.