Iron-doped cobalt oxide nanoarray for efficient electrocatalytic nitrate-to-ammonia conversion

Electrochemical nitrate reduction reaction (NO₃RR) is an attractive alternative to NH₃ production under ambient conditions. Although noble metal-based catalysts exhibit decent NO₃RR performance to NH₃, the high cost and insufficient supply obstruct its large-scale application. In this work, we report that Fe-doped Co₃O₄ nanoarray efficiently catalyzes NO₃RR for NH₃ production in neutral conditions. It achieves a large NH₃ yield of 0.624 mg mg_cat.^-1h^-1 and high Faradaic efficiency of 95.5% at -0.7 V versus reversible hydrogen electrode. Besides, this catalyst exhibits good NO₃RR stability. Density functional theory calculations reveal favorable adsorption of NO₃^- on Fe-doped Co₃O₄, which is conducive to NH₃ production in the NO₃RR process.