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 mgcat.−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.