Chinese Journal of Catalysis ›› 2024, Vol. 62: 231-242.DOI: 10.1016/S1872-2067(24)60059-8

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Manipulating the interactions between N-intermediates and one-dimensional conjugated coordination polymers to boost electroreduction of nitrate to ammonia

Qing Liua,1, Xue-Feng Chenga,1, Jin-Yan Huoa, Xiao-Fang Liua, Huilong Dongb,*(), Hongbo Zengc, Qing-Feng Xua,*(), Jian-Mei Lua,*()   

  1. aCollege of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215123, Jiangsu, China
    bSchool of Materials Engineering, Changshu Institute of Technology, Changshu 215500, Jiangsu, China
    cDepartment of Chemical and Materials Engineering, University of Alberta, Edmonton, Canada
  • Received:2024-03-31 Accepted:2024-05-23 Online:2024-07-18 Published:2024-07-10
  • Contact: E-mail: huilong_dong@126.com (H. Dong), xuqingfeng@suda.edu.cn (Q.-F. Xu), lujm@suda.edu.cn (J.-M. Lu).
  • About author:1 Contributed to this work equally.
  • Supported by:
    Basic Research Project of Leading Technology in Jiangsu Province(BK20202012);National Natural Science Foundation of China(21938006);National Natural Science Foundation of China(51773144);Natural Science Foundation of the Jiangsu Higher Education Institutions of China(20KJA610001);Priority Academic Program Development of Higher Education Institutions (PAPD) in Jiangsu(PAPD);National Center for International Research on Intelligent Nano-Materials and Detection Technology in Environmental Protection, Soochow University(SDGH2303)

Abstract:

Electrocatalytic reduction of nitrate to ammonia (NITRR) is a promising strategy to remove nitrate pollutants and generate ammonia under mild conditions. However, the low conversion rate of nitrate and insufficient ammonia production rate severely limits the development of NITRR. Manipulating the adsorption of N-intermediates on the surface of catalyst greatly affects the activity and the selectivity of catalytic reaction. Herein, four one-dimensional π-d conjugated coordination polymers (1D CCPs) are synthesized and applied to NITRR. The selectivity and activity of NITRR are well improved by metal ion substitutions, which regulate the adsorption towards generated intermediates. The ammonia production rate reaches 2.28 mg h-1 cm-2 over Cu-BTA in 2 h, comparable to recent works at low nitrate concentrations, and the conversion rate of nitrate up to 96.74% in four hours with 79.46% ammonia selectivity. Density functional theory calculations reveal that Cu-BTA had electron-richer Cu center, causing the enhanced free energy of *NO and the attenuation of N=O bond. Therefore, the ΔG required for converting *NO to *NHO is reduced and the further hydrogenation is promoted. Additionally, the adsorption energies toward NH3 are also effectively reduced by metal ions substitution, accelerating the desorption of generated and adsorbed NH3, making the turnover of catalysts more frequent.

Key words: Nitrate reductionAmmonia synthesis, Electrocatalysis, One-dimensional conjugated, coordination polymers, Adsorption manipulation