CeO2 nanoparticles with oxygen vacancies decorated N-doped carbon nanorods: A highly efficient catalyst for nitrate electroreduction to ammonia
Zerong Li, Zhiqin Deng, Ling Ouyang, Xiaoya Fan, Longcheng Zhang, Shengjun Sun, Qian Liu, Abdulmohsen Ali Alshehri, Yonglan Luo, Qingquan Kong, Xuping Sun
Abstract
Electrocatalytic nitrate reduction reaction (NO3−RR) emerges as a highly efficient approach toward ammonia synthesis and degrading NO3− contaminant. In our study, CeO2 nanoparticles with oxygen vacancies (VO) decorated N-doped carbon nanorods on graphite paper (CeO2−x@NC/GP) were demonstrated as a highly efficient NO3−RR electrocatalyst. The CeO2−x@NC/GP catalyst manifests a significant NH3 yield up to 712.75 µmol·h−1cm−2 at −0.8 V vs. reversible hydrogen electrode (RHE) and remarkable Faradaic efficiency of 92.93% at −0.5 V vs. RHE under alkaline conditions, with excellent durability. Additionally, an assembled Zn-NO3− battery with CeO2−x@NC/GP as cathode accomplishes a high-power density of 3.44 mWcm−2 and a large NH3 yield of 145.08 µmol·h−1cm−2. Density functional theory results further expose the NO3− reduction mechanism on CeO2 (111) surface with VO.