Heterostructured Co/Co3O4 anchored on N-doped carbon nanotubes as a highly efficient electrocatalyst for nitrate reduction to ammonia

Xianxian He; Hongfei Liu; Jiangzhou Qin; Zhaodong Niu; Jincheng Mu; Baojun Liu

doi:10.1039/d3dt01705b

Heterostructured Co/Co₃O₄ anchored on N-doped carbon nanotubes as a highly efficient electrocatalyst for nitrate reduction to ammonia

Dalton Trans. 2023 Aug 8;52(31):10869-10875. doi: 10.1039/d3dt01705b.

Authors

Xianxian He¹, Hongfei Liu¹, Jiangzhou Qin², Zhaodong Niu³, Jincheng Mu¹, Baojun Liu¹

Affiliations

¹ College of Resource and Environmental Engineering, Guizhou University, Guiyang 550025, China.
² Department of Environmental Engineering, Peking University, The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, China.
³ Key Laboratory of Industrial Ecology and Environmental Engineering, School of Environmental Science & Technology, Dalian University of Technology, Dalian 116024, China.

PMID: 37486287
DOI: 10.1039/d3dt01705b

Abstract

The electrochemical reduction of nitrate (NO₃^-) to ammonia (NH₃) has emerged as an attractive approach for selectively reducing NO₃^- to highly value-added NH₃ and removing NO₃^- pollutants simultaneously. In this work, a heterostructured Co/Co₃O₄ electrocatalyst anchored on N-doped carbon nanotubes was prepared and applied for the NO₃^- reduction towards NH₃ under alkaline conditions. The catalyst achieves outstanding performance with up to 67% NH₃ faradaic efficiency at -1.2 V vs. Hg/HgO and 8.319 mg h^-1 mg_cat^-1 yield at -1.7 V vs. Hg/HgO. In addition, it also exhibits good long-term stability. ¹⁵N isotopic labelling experiments prove that the yielded NH₃ is derived from NO₃^- species. In situ electrochemical Raman spectra revealed that the structure of the as-prepared catalyst showed outstanding stability and identified possible intermediates during the electrocatalytic NO₃^- reduction reaction (NO₃RR).