Fe and Cu Double-Doped Co3O4 Nanorod with Abundant Oxygen Vacancies: A High-Rate Electrocatalyst for Tandem Electroreduction of Nitrate to Ammonia

Maosen Song; Yuxuan Xing; Yudong Li; Dan Liu; Enshan Han; Yang Gao; Ziyi Yang; Xiaohui Yang; Yanzhen He

doi:10.1021/acs.inorgchem.3c02834

Fe and Cu Double-Doped Co₃O₄ Nanorod with Abundant Oxygen Vacancies: A High-Rate Electrocatalyst for Tandem Electroreduction of Nitrate to Ammonia

Inorg Chem. 2023 Oct 9;62(40):16641-16651. doi: 10.1021/acs.inorgchem.3c02834. Epub 2023 Sep 22.

Authors

Maosen Song¹, Yuxuan Xing¹, Yudong Li², Dan Liu², Enshan Han¹, Yang Gao¹, Ziyi Yang¹, Xiaohui Yang³, Yanzhen He¹

Affiliations

¹ School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China.
² Key Laboratory of Bio-based Material Science & Technology, Northeast Forestry University, Harbin 150040, China.
³ Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China.

PMID: 37738294
DOI: 10.1021/acs.inorgchem.3c02834

Abstract

The electrochemical nitrate reduction reaction (NO₃RR) is an attractive green alternative to the conventional Haber-Bosch method for the synthesis of NH₃. However, this reaction is a tandem process that involves multiple steps of electrons and protons, posing a significant challenge to the efficient synthesis of NH₃. Herein, we report a high-rate NO₃RR electrocatalyst of Fe and Cu double-doped Co₃O₄ nanorod (Fe₁/Cu₂-Co₃O₄) with abundant oxygen vacancies, where the Cu preferentially catalyzes the rapid conversion of NO₃^- to NO₂^- and the oxygen vacancy in the Co₃O₄ substrate can accelerate NO₂^- reduction to NH₃. In addition, the introduction of Fe can efficiently capture atomic H* that promotes the dynamics of NO₂^- to NH₃, improving Faradaic efficiency of the produced NH₃. Controlled experimental results show that the optimal electrocatalyst of Fe₁/Cu₂-Co₃O₄ exhibits good performance with high conversion (93.39%), Faradaic efficiency (98.15%), and ammonia selectivity (98.19%), which is significantly better than other Co-based materials. This work provides guidance for the rational design of high-performance NO₃RR catalysts.