The Problem of the Anode Electrolyte in H-Type Electrolytic Cell for Electrochemical Reduction of Carbon Dioxide

Authors

Rui ZHANG, School of Chemical Engineering and Technology, Harbin Institute of Technology, No.92 West-Da Zhi Street, Harbin, 150001 China;College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin, 150001 China;Chaowei Power Co., LTD, Changxing, 313100 China;
Wei-xin LV, School of Chemistry and Chemical Engineering, Yancheng Institute of Technology, Yancheng 224051, Jiangsu, China;
Li-xu LEI, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China;Follow

Corresponding Author

Li-xu LEI(lixu.lei@seu.edu.cn)

Abstract

Electrochemical reduction of carbon dioxide (CO₂) was studied in the H-type electrolytic cell. It was found that the voltage between the cathode and the anode would increase during the long time electrolysis process, for this reason the electrolytic process would be unsustainable. After the experimental investigations carried out by constant potential electrolysis, constant current electrolysis, pH test and KHCO₃ concentration analysis of anode electrolyte before and after the electrolysis, the increase in cell voltage might be caused by the following process: H⁺, that was generated from the anodic oxygen evolution reaction, reacted with HCO₃^- to form water and CO₂, and the HCO₃^-in the anode chamber was consumed; then K⁺ in the anode chamber was forced to spread into the cathode chamber which led to the decrease of the electrolyte concentration in the anode chamber. Therefore, the conductivity of the electrolyte solution in the anode chamber decreased, resulting in the rise of the anode potential. This phenomenon may happen in the alkaline electrolyte in an anode cell, therefore, in order to ensure the electrolysis process sustainable and keep high energy conversion efficiency, the anode electrolyte cannot be any alkaline substance.

Graphical Abstract

Keywords

H-type electrolytic cell, proton exchange membrane, carbon dioxide, electrochemical reduction, oxygen evolution

DOI Link

https://doi.org/10.13208/j.electrochem.160121

Publication Date

2017-02-28

Online Available Date

2016-06-20

Revised Date

2016-06-14

Received Date

2016-01-21

Recommended Citation

Rui ZHANG, Wei-xin LV, Li-xu LEI. The Problem of the Anode Electrolyte in H-Type Electrolytic Cell for Electrochemical Reduction of Carbon Dioxide[J]. Journal of Electrochemistry, 2017 , 23(1): 72-79.
DOI: 10.13208/j.electrochem.160121
Available at: https://jelectrochem.xmu.edu.cn/journal/vol23/iss1/10