Rational design of artificial Lewis pairs coupling with polyethylene glycol for efficient electrochemical ammonia synthesis

Haifan Wang; Menglei Yuan; Jingxian Zhang; Yiling Bai; Ke Zhang; Bin Li; Guangjin Zhang

doi:10.1016/j.jcis.2023.06.097

Rational design of artificial Lewis pairs coupling with polyethylene glycol for efficient electrochemical ammonia synthesis

J Colloid Interface Sci. 2023 Nov:649:166-174. doi: 10.1016/j.jcis.2023.06.097. Epub 2023 Jun 17.

Authors

Haifan Wang¹, Menglei Yuan², Jingxian Zhang¹, Yiling Bai³, Ke Zhang⁴, Bin Li⁵, Guangjin Zhang⁶

Affiliations

¹ CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China; Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
² CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China; Northwestern Polytechnical University, Xian 710000, China.
³ State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China; SynCat@Beijing, Synfuels China Technology Co. Ltd., Beijing 101407, China.
⁴ Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou 450001, China.
⁵ Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou 450001, China. Electronic address: lib@ztri.com.cn.
⁶ CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China; Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: zhanggj@ipe.ac.cn.

PMID: 37348336
DOI: 10.1016/j.jcis.2023.06.097

Abstract

Ammonia (NH₃) synthesis at mild conditions by electrocatalytic nitrogen reduction (eNRR) has received more attention and has been regarded as a promising alternative to the traditional Haber-Bosch process. Lewis acid-base pairs (LPs) can chemisorb and react with nitrogen by electronic interaction, while the tuning of the microenvironment near electrode can hinder hydrogen evolution reaction (HER) thus improving the selectivity of the eNRR. Herein, the FeOOH nanorod coupled with LPs on the surface (i.e., Fe, Fe-O) was synthesized, which could effectively drive eNRR. Meanwhile, polyethylene glycol (PEG) was introduced to serve as a local non-aqueous electrolyte system to inhibit HER. The prepared FeOOH-150 catalyst achieved outstanding eNRR performance with an NH₃ yield rate of 118.07 μg h^-1mg_cat^-1 and a Faradaic efficiency of 51.4 % at -0.6 V vs. RHE in 0.1 M LiClO₄ + 20 % PEG. Both the experiment and DFT calculations revealed that the interaction of PEG with Lewis base sites could optimize nitrogen adsorption configuration and activation.

Keywords: Electrochemical nitrogen reduction; Lewis acid-base pairs; Nitrogen adsorption configuration; Polyethylene glycol (PEG).