权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Development of Energy-saving Process of Chlor-Alkali Membrane Cell with Gas-diffusion Electrode

气体扩散电极氯碱膜电池节能工艺的开发

基本信息

批准号：
12355030
负责人：
SUDOH Masao
金额：
$ 25.93万
依托单位：
Shizuoka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12355030/
关键词：
Gas-diffusion electrode Electrochemical process Chlor-alkali industry Energy saving

项目摘要

Oxygen depolarized cathodes with gas-diffusion electrode has been expected as an excellent method for soda electrolysis because of its energy-saving and CO_2-reducing. Replacing hydrogen-evolving cathodes with oxygen cathodes significantly reduces cell voltage, which is the potential difference of these electrode reactions. The use of oxygen cathodes can lead to energy saving of 30 to 40 %. However, oxygen cathodes using gas diffusion electrode have not been practically applied yet. As one of the reasons, when a gas diffusion electrode is used in high concentrated alkaline solution at high temperature, the electrolyte solution penetrates to the gas supply layer in the gas diffusion electrode during electrolysis period. The penetration of the alkaline solution changes the electrode performance because of the decrease in the interface area of the gas-liquid-solid phase at the reaction site. The kinetics of oxygen reduction on a gas diffusion electrode has been extensively investigated, b … More ut basic data in developing the new gas diffusion electrode have not been obtained because of the quantitative data on the electrode characteristic or the mechanism of the electrode degradation are not sufficient. Therefore, it is necessary to have quantification of the electrode degradation. The purpose of this study is to improve the stability of gas-diffusion electrode for high concentrated alkaline solution at high temperature. The cathodic properties of oxygen reduction on the gas diffusion electrode were examined by AC impedance method using an equivalent circuit. The effect of the penetration of the electrolyte into gas diffusion electrode was determined quantitatively by using charge-transfer resistance and the double-layer capacitance. Comparing the electrodes using Ag and Pt catalysts of different life time, the cathode potentials and the diameter of the Nyquist plots were increased with increasing life time. The electrode characteristics using Ag catalyst was more excellent than using Pt catalyst. The surfaces of the gas diffusion electrodes were analyzed by XPS. The surfaces of the electrodes on carbon, PTFE and silver were failed away and adsorbed sodium and oxygen. The mechanism of the electrode degradation was discussed by the cathodic overpotential simulation. The increase of cathodic overpotential was affected by increasing the thickness of the thin-film than the penetration of the electrolyte into gas diffusion layer. Less

气体扩散电极氧去极化阴极由于其节能和减少co_2的特点，被认为是一种很好的碱电解方法。用氧阴极代替析氢阴极显著降低了电池电压，这是两种电极反应的电位差。使用氧阴极可以节省30%到40%的能源。然而，采用气体扩散电极的氧阴极尚未得到实际应用。其中一个原因是，当气体扩散电极在高温高浓度碱性溶液中使用时，电解过程中电解质溶液渗透到气体扩散电极的供气层。碱溶液的渗透使反应部位气液固界面面积减小，从而改变了电极的性能。氧气在气体扩散电极上的还原动力学已经得到了广泛的研究，但由于对电极特性和电极降解机理的定量数据还不充分，尚未获得开发新型气体扩散电极的更多基础数据。因此，有必要对电极的降解进行定量分析。本研究的目的是提高气体扩散电极在高温下对高浓度碱性溶液的稳定性。采用等效电路，用交流阻抗法研究了氧在气体扩散电极上的阴极性能。利用电荷转移电阻和双层电容定量测定了电解质对气体扩散电极的渗透效应。对比使用不同寿命的Ag和Pt催化剂的电极，阴极电位和Nyquist图的直径随着寿命的增加而增加。Ag催化剂的电极性能优于Pt催化剂。用XPS对气体扩散电极表面进行了分析。电极表面的碳、聚四氟乙烯和银被腐蚀掉并吸附了钠和氧。通过阴极过电位模拟，探讨了电极降解的机理。阴极过电位的增加主要受薄膜厚度的增加而非电解质对气体扩散层的渗透的影响。少