A nanoporous CeO2nanowire array by acid etching preparation: An efficient electrocatalyst for ambient N2reduction

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-1cat. 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.