A nanoporous CeO2 nanowire array by acid etching preparation: an efficient electrocatalyst for ambient N2 reduction

Abstract

It is highly attractive but still remains a key challenge to develop earth-abundant electrocatalysts for efficient NH₃ electrosynthesis via the N₂ reduction reaction (NRR). In this work, a nanoporous CeO₂ nanowire array on a Ti mesh (np-CeO₂/TM) was derived from MnO₂–CeO₂/TM by acid etching of MnO₂ that acts as a pore-forming agent. In 0.1 M HCl, this catalyst achieves a high faradaic efficiency of 4.7% with a NH₃ yield of 38.6 μg h⁻¹ mg⁻¹_cat. at −0.3 V vs. reversible hydrogen electrode, outperforming most reported Ce-based NRR electrocatalysts under ambient conditions. It also demonstrates high electrochemical stability and excellent selectivity for NH₃ generation. The acid preparation strategy is highly valuable for future design of active NRR catalysts with desired compositions in various electrocatalysis fields.