CeO2 nanoparticles with oxygen vacancies decorated N-doped carbon nanorods: A highly efficient catalyst for nitrate electroreduction to ammonia

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 (V-O) 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 mu mol.h(-1)cm(-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 mu mol.h(-1)cm(-2). Density functional theory results further expose the NO3- reduction mechanism on CeO2 (111) surface with V-O.