Performance Improvement of the Liquid-Fed So2-Depolarized Electrolysis Cells for High H2so4 Concentration Anolyte

作     者：Ding, Xifeng Ma, Xiaoshan Zhang, Ping Qu, Yongshui Wang, Laijun Chen, Songzhe 

作者机构：Institute of Nuclear and New Energy Technology Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education Tsinghua University Beijing100084 China State Key Laboratory of Biochemical Engineering Institute of Process Engineering Chinese Academy of Sciences Beijing100190 China College of Chemical Engineering Beijing University of Chemical Technology Beijing100029 China 

出 版 物：《SSRN》 

年 卷 期：2022年

核心收录：

主　　题：Electrolysis 

摘      要：In hybrid sulfur (HyS) process, it is very important for the SO2-depolarized electrolysis (SDE) to be in operation with high H2SO4 concentration anolyte, aiming at the high efficiency hydrogen production. However, the SDE cell is facing the challenge of high impedance when H2SO4 concentration is increased. In this study, the performance of liquid-fed SDE cells is improved by reducing the proton exchange membrane (PEM) thickness, as well as the application of three-dimensional anode. 4 SDE cells with different configurations are assembled, tested and compared. The electrochemical impedance spectroscopy (EIS) is used to study the cells’ impedance compositions. The results showed that effectively reducing the concentration polarization impedance is the key to improve the SDE performance. By replacing the Nafion 117 (175 μm thick) PEM with thinner Nafion 212 (50 μm thick), together with the help of Pt-loaded graphite felt as three-dimensional anode, the cell’s performance under high H2SO4 concentration anolyte condition is significantly improved. The maximum current density of the electrolyzer could reach 560mA/cm2 at 1.0 V using anolyte with 50 wt.% H2SO4 concentration. © 2022, The Authors. All rights reserved.