摘要
质子交换膜(PEM)电解水过程中氢的跨膜渗透是制约电解水效率和安全性的重要因素。制备了5种不同厚度的PEM,阐明了PEM厚度对PEM电解水中氢气渗透性的影响规律,并通过对比进一步研究了PEM的主要结构特征物理量(吸水量(S)、结晶度(Xc)和亲水域平均间距(Dw))对氢气渗透性的影响机制。研究结果表明,上述3个特征物理量对氢气渗透性能均有较大影响,其中Dw是影响氢气渗透性能的主要因素。
Proton exchange membrane(PEM)water electrolysis presents a blueprint for high-efficiency green hydrogen production.However,hydrogen(H2)permeation across the PEM poses challenges to the efficiency and safety of PEM water electrolysis.Herein,we investigated the hydrogen permeation process on the prepared perfluorinated sulfonic acid(PFSA)membrane with a thickness range from 50μm to 180μm,demonstrating the influence mechanism of PEM structure on hydrogen permeation.Five kinds of perfluorinated sulfonic acid PEM with different thickness were cast from Nafion D520 dispersion into quartz vessels.Membrane electrode assembly(MEA)was assembled into a single cell by a hot press transfer method.Electrochemical tests and gas chromatography were used to validate the influence of the thickness of PEM on the cell performance and H2 permeation of PEM water electrolysis.The permeation of H2 is not simply inversely proportional to the thickness of the films,which may be due to structural differences between films.To further elucidate the modulating mechanism of PEM structure on H2 permeation,the relative crystallinity of the membrane and the mean spacing between the hydrophilic water-domains were tested through X-ray diffraction and scattering experiments.Additionally,grey correlation analysis(a mathematical statistical analysis method)was performed on the collected data.The analysis revealed the prominent modulating effect of the membrane structure parameters water content(S),crystallinity(Xc)and water-domains spacing(Dw)on the H2 permeation,with Dw identified as the primary factor affecting H2 permeation.These parameters influence the size and connectivity of the hydrophilic water-domains within the membrane impacting the size and length of the H2 diffusion path and resulting in differences in hydrogen diffusion rate.This study aimed to investigate the influence mechanism of proton exchange membrane structure on hydrogen permeation,offering fresh perspectives on research into the hydrogen permeation performance of proton exchange membranes.Our study offers a guidance for researchers in the development of cost-effective and secure membranes for use in PEM water electrolysis.
作者
郭洋
王佳
郭伟
李俊升
GUO Yang;WANG Jia;GUO Wei;LI Junsheng(School of Materials Science and Engineering,Chemical Engineering and Life Sciences,Wuhan University of Technology,Wuhan 430070,China;School of Chemistry,Chemical Engineering and Life Sciences,Wuhan University of Technology,Wuhan 430070,China)
出处
《功能高分子学报》
CAS
CSCD
北大核心
2024年第1期23-31,共9页
Journal of Functional Polymers
基金
国家自然科学基金(52271226)。
关键词
全氟磺酸
质子交换膜
电解水
氢气渗透性
电解池
perfluorosulfonic acid
proton exchange membrane
water electrolysis
hydrogen permeation
electrolyzer