高等学校化学学报 ›› 2019, Vol. 40 ›› Issue (9): 1847-1856.doi: 10.7503/cjcu20190166

• 分析化学 • 上一篇    下一篇

醌类衍生物捕获CO2的红外光谱电化学研究

范慧,金葆康()   

  1. 安徽大学化学化工学院, 合肥 230601
  • 收稿日期:2019-03-20 出版日期:2019-09-10 发布日期:2019-07-16
  • 通讯作者: 金葆康 E-mail:bkjinhf@aliyun.com
  • 基金资助:
    国家自然科学基金(21175001, 21375001)

Investigation on Electrochemical Capture of CO2 by Quinone Derivatives Based on in situ FTIR Spectroelectrochemistry

FAN Hui,JIN Baokang()   

  1. School of Chemistry & Chemical Engineering, Anhui University, Hefei 230601, China
  • Received:2019-03-20 Online:2019-09-10 Published:2019-07-16
  • Contact: JIN Baokang E-mail:bkjinhf@aliyun.com
  • Supported by:
    ? Supported by the National Natural Science Foundation of China(21175001, 21375001)

摘要:

采用现场红外光谱电化学技术, 研究了2,6-二氯苯醌(DCBQ)和2,6-二甲氧基苯醌(DMOBQ)在乙腈溶液中对CO2的电化学捕获过程. 结果表明, 2种醌类衍生物在乙腈溶液中的电化学循环伏安(CV)曲线呈现2对氧化还原峰, 遵循连续两步单电子过程. 加入CO2后, 由于取代基亲电性的不同, 2种衍生物发生了不同的变化: DCBQ仍然呈现2对氧化还原峰, 但是第二对还原峰发生了正移动; 而DMOBQ的2对氧化还原峰变成1对峰. 根据现场红外光谱分析结果分别得到了DCBQ和DMOBQ电化学捕获CO2过程的不同机理. DCBQ是二价阴离子发生化学变化的电化学-电化学-化学(EEC)机理, 而DMOBQ则是还原产物一价阴离子自由基参与化学变化的电化学-化学-电化学(ECE)机理. 进一步对CO2捕获过程进行了定量分析, 得出2种反应的化学计量比均为1∶1.

关键词: 现场红外光谱电化学, 2, 6-二氯苯醌, 2, 6-二甲氧基苯醌, 二氧化碳电化学捕获, 氧化还原机理

Abstract:

The electrochemical capture process of CO2 by quinone derivatives, 2,6-dichloro-1,4-benzoquinone(DCBQ) and 2,6-dimethoxy-1,4- benzoquinone(DMOBQ), in acetonitrile solutions were investigated by in situ FTIR spectroelectrochemistry. There are two well-defined couples of redox peaks of both derivatives in acetonitrile solvent in cyclic voltammetry curve(CV), which indicates that the electrochemical reactions undergo two-step one-electron transfer. Due to the different electrophilicity of substituent, the quinone derivatives react with CO2 through different process after the addition of CO2. The CV of DCBQ still presents two couples of redox peaks with the second couple of redox peaks shifts positively; while only one couple of redox peaks appears in the CV of DMOBQ. The results of in situ FTIR experiments further indicated the different mechanisms of capture CO2 by DMOBQ and DCBQ. DCBQ undergoes the EEC mechanism, in which CO2 is captured by the two-step one-electron reduction products dianion DCBQ 2-. However, DMOBQ undergoes ECE mechanism to capture CO2 by the one electron transfer product anion radical DMOBQ ·-. Furthermore, the quantitative analysis of the reduction products of capture CO2 was carried out. The stoichiometric is 1:1 to the two derivatives.

Key words: In situ FTIR spectroelectrochemistry, 2, 6-Dichloro-1, 4-benzoquinone, 2, 6-Dimethoxy-1, 4-benzoquinone, Carbon dioxide electrochemical capture, Redox mechanism

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