Oxygen Vacancies of CeO<sub>2</sub> Nanospheres by Mn-Doping: An Efficient Electrocatalyst for N<sub>2</sub> Reduction under Ambient Conditions
Yuyao Ji, Wendong Cheng, Chengbo Li, Xingquan Liu
Abstract
The electrochemical N2 reduction reaction (NRR) demonstrates a process of NH3 synthesis from N2 molecules under ambient conditions, which is environmentally friendly and recyclable. However, it requires an efficient electrocatalyst to activate inert N2 molecules, which is still difficult to satisfy. Recently, as an active NRR electrocatalyst and a typical metal oxide, CeO2 has featured ultrahigh thermal stability and the ability to apply heteroatom doping, which is an imperative approach importing oxygen vacancy by replacing metal ions with selective elements to greatly influence the activity of catalysts. Here, we analyze the unique properties of manganese dopants in modulating the activity of CeO2 nanospheres for NRR. It attains a larger NH3 yield of 27.79 μg h–1 mgcat–1 and a higher Faradaic efficiency of 9.1% than pure CeO2 at −0.30 V in 0.1 M HCl, with high electrochemical and structure stability. With calculations by density functional theory, the performance enhancement of Mn-doped CeO2 is also proved mathematically.