Boosting electrocatalytic N2 reduction to NH3 on β-FeOOH by fluorine doping

Xiaojuan Zhu; Zaichun Liu; Huanbo Wang; Runbo Zhao; Hongyu Chen; Ting Wang; Faxing Wang; Yonglan Luo; Yuping Wu; Xuping Sun

doi:10.1039/c9cc00647h

Boosting electrocatalytic N₂ reduction to NH₃ on β-FeOOH by fluorine doping

Chem Commun (Camb). 2019 Apr 7;55(27):3987-3990. doi: 10.1039/c9cc00647h. Epub 2019 Mar 18.

Authors

Xiaojuan Zhu¹, Zaichun Liu², Huanbo Wang³, Runbo Zhao⁴, Hongyu Chen⁴, Ting Wang⁴, Faxing Wang⁵, Yonglan Luo¹, Yuping Wu², Xuping Sun⁶

Affiliations

¹ Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, College of Chemistry and Chemical Engineering, China West Normal University, Nanchong 637002, Sichuan, China. luoylcwnu@hotmail.com.
² State Key Laboratory of Materials-oriented Chemical Engineering, and School of Energy Science and Engineering, and Institute for Advanced Materials, Nanjing Tech University, Nanjing 211816, Jiangsu, China. wuyp@fudan.edu.cn.
³ School of Environment and Resource, Southwest University of Science and Technology, Mianyang 621010, China.
⁴ Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan, China. xpsun@uestc.edu.cn.
⁵ Department of Chemistry and Food Chemistry & Center for Advancing Electronics Dresden (cfaed), Technische Universität, Dresden 01062, Dresden, Germany.
⁶ Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, College of Chemistry and Chemical Engineering, China West Normal University, Nanchong 637002, Sichuan, China. luoylcwnu@hotmail.com and Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan, China. xpsun@uestc.edu.cn.

PMID: 30882131
DOI: 10.1039/c9cc00647h

Abstract

As the cheapest and one of the most abundant transition metals, Fe is not only involved in nitrogenases for biological N₂ fixation but is also extensively utilized in the Haber-Bosch process for industrial-scale NH₃ synthesis. However, the application of Fe-based electrocatalysts for ambient N₂-to-NH₃ conversion still requires exploration of effective strategies to boost the catalytic performances for simultaneously achieving a large NH₃ yield and a high Faradaic efficiency (FE). Here, we report that the ambient electrocatalytic N₂ reduction activity of a β-FeOOH nanorod can be greatly improved by fluorine doping. When tested at -0.60 V vs. reversible hydrogen electrode (RHE) in 0.5 M LiClO₄, such a β-FeO(OH,F) nanorod obtains an optimal NH₃ yield (42.38 μg h^-1 mg_cat.^-1) and FE (9.02%), much higher than those of pristine β-FeOOH (10.01 μg h^-1 mg_cat.^-1, 2.16%). Density functional theory calculations reveal that the enhancement in activity originates from the lower reaction energy barrier (0.24 eV) of the nanorod than that of β-FeOOH (0.59 eV).