Nb-doped NiO nanoflowers for nitrite electroreduction to ammonia

Ying Zhang; Yuying Wan; Xiaoxu Liu; Kai Chen; Ke Chu

doi:10.1016/j.isci.2023.107944

Nb-doped NiO nanoflowers for nitrite electroreduction to ammonia

iScience. 2023 Sep 19;26(10):107944. doi: 10.1016/j.isci.2023.107944. eCollection 2023 Oct 20.

Authors

Ying Zhang¹, Yuying Wan¹, Xiaoxu Liu², Kai Chen¹, Ke Chu¹

Affiliations

¹ School of Materials Science and Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China.
² College of Science, Hebei North University, Zhangjiakou, Hebei 075000, China.

Abstract

Electrocatalytic reduction of nitrite to ammonia (NO₂RR) is considered as an appealing route to simultaneously achieve sustainable ammonia production and abate hazardous nitrite pollution. Herein, atomically Nb-doped NiO nanoflowers are designed as a high-performance NO₂RR catalyst, which exhibits the highest NH₃-Faradaic efficiency of 92.4% with an NH₃ yield rate of 200.5 μmol h^-1 cm^-2 at -0.6 V RHE. Theoretical calculations unravel that Nb dopants can act as Lewis acid sites to render effective NO₂^- activation, decreased protonation energy barriers, and restricted hydrogen evolution, ultimately leading to a high NO₂RR selectivity and activity.

Keywords: Applied chemistry; Electrochemistry; Energy materials.