Cu doping in CeO2 to form multiple oxygen vacancies for dramatically enhanced ambient N2 reduction performance

Abstract

Here, we report the synthesis of Cu-doped CeO₂ nanorods (denoted as Cu-CeO₂-x, x represents the mass content (wt%) of the doped Cu) by a facile hydrothermal method, followed by thermal treatment in an H₂/Ar atmosphere. As the electrocatalyst, Cu-CeO₂-3.9 with a large surface area of 95.2 m² g⁻¹ and mesoporous structure exhibits high electrocatalytic activity toward the N₂ reduction reaction (NRR), delivering an NH₃ yield rate of 5.3 × 10⁻¹⁰ mol s⁻¹ cm⁻² and a faradaic efficiency of 19.1% at −0.45 V (vs. RHE) in a 0.1 M Na₂SO₄ electrolyte (pH = 6.3), much higher than the NRR performance achieved with pure CeO₂ nanorods. The Cu doping can effectively tune the concentration of multiple oxygen vacancies in CeO₂, thus resulting in significantly improved NRR activity.