Energy Storage Science and Technology ›› 2022, Vol. 11 ›› Issue (6): 1947-1956.doi: 10.19799/j.cnki.2095-4239.2022.0025

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Electrocatalytic performances of Ru nanoparticles supported on carbon nanotubes by colloidal solution for synthetic ammonia

XIE Chenglu1(), HUANG Xiankun1,2(), KANG Lixia1,2, LIU Yongzhong1,2()   

  1. 1.School of Chemical Engineering and Technology, Xi'an Jiao Tong University
    2.Engineering Research Center of New Energy System Engineering and Equipment, University of Shaanxi Province, Xi'an 710049, Shaanxi, China
  • Received:2022-01-13 Revised:2022-01-28 Online:2022-06-05 Published:2022-06-13
  • Contact: HUANG Xiankun, LIU Yongzhong E-mail:xcllll@stu.xjtu.edu.cn;xkhuang@mail.xjtu.edu.cn;yzliu@mail.xjtu.edu.cn

Abstract:

Colloidal solution can be used to reduce Ru nanoparticles. The catalyst for electrochemical ammonia synthesis was Ruc/CNT, which was created by supporting Ru nanoparticles on carbon nanotubes(CNT). By varying the volume of the Ru colloid solution, different Ru loadings of the Ruc/CNT can be obtained. Catalyst were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM), contact angle meter, and electrochemical techniques. The results show that the Ru nanoparticles on Ruc/CNT prepared by colloidal solution are smaller (1-5 nm) and disperse better than those on Ru/CNT. 0.025-Ruc/CNT with a Ru load of 2.5% achieved the highest ammonia yield of 10.98 μg/(h·mgcat.) and a Faraday efficiency of 2.18%. Nonetheless, Ru/CNT prepared by directly reducing Ru on carbon nanotubes had an ammonia yield of 5.19 μg/(h·mgcat.) and a Faraday efficiency of 0.05%. Control experiments confirmed the source of the ammonia. The findings demonstrated that ammonia was produced by an electrochemical catalytic nitrogen reduction reaction. Ru nanoparticles are the catalyst's primary active sites. Reducing the size of Ru particles promotes charge transfer between the carrier and the Ru nanoparticles, weakens the high-energy N≡N triple bonds in the reaction process, and improves ammonia selectivity. CNT application provides sufficient loading sites for 0.025-Ruc/CNT, and Ru nanoparticles with greater dispersion can expose more active sites. As a result, 0.025-Ruc/CNT performs better for electrochemical ammonia synthesis.

Key words: catalyst, electrochemistry, nitrogen reduction, ammonia synthesis, SCR, nanoparticles

CLC Number: