摘要
目的为了提高双极板在质子交换膜燃料电池(PEMFC)工作环境下的耐蚀性。方法在1-乙基-3-甲基咪唑磷酸二乙酯盐([EMIM][DEP])离子液体中,在316 L不锈钢(SS)基体上电聚合聚苯胺(PANI)膜。用红外光谱(FTIR)、拉曼光谱(Raman)、X射线光电子能谱(XPS)和扫描电子显微镜(SEM)进行微观结构表征。通入氢气(H2)模拟阳极反应气氛,控制电位为−0.1 V(vs.SCE),模拟阳极工作电位,采用开路电位(OCP)、电化学阻抗谱(EIS)和极化曲线研究H_(2)对PANI/316 L SS双极板腐蚀性能的影响。结果FTIR显示有苯环、醌环、P==O和—COOH伸缩振动,Raman显示有掺杂态半醌自由基C—N+·伸缩振动,XPS表明PANI膜含有C、N、O和P等元素。极化曲线腐蚀电流密度按照H_(2)>N_(2)>O_(2)(DO)依次增大,EIS容抗弧半径按照H_(2)<N_(2)<O_(2) O_(2)(DO)依次减小。H2环境使PANI/316 L SS体系OCP下降0.06 V,电荷转移电阻(Rct)值下降55Ω/cm^(2),自腐蚀电位下降0.3 V左右。结论PANI具有中间氧化态结构,(CH_(3)CH_(2))_(2)PO_(4)−和HOOC—COO−作为“对阴离子”在PANI中发生共掺杂。在PEMFC阳极工作电位下,H_(2)对PANI/316 L SS耐蚀性有显著影响,H2使PANI膜发生还原,—N+==与—N+H—的和与总N原子含量的比值(N+/N值)下降1.4%,导致PANI分子链中的“对阴离子”发生脱掺杂,PANI/316 L SS体系耐蚀性下降。
The work aims to improve the corrosion resistance of bipolar plates in the working environment of proton exchange membrane fuel cell(PEMFC).Polyaniline(PANI)films were electropolymerized on 316 L stainless steel(SS)matrix in 1-ethyl3-methylimidazole diethyl phosphate([EMIM][DEP])ionic liquid.The microstructure was characterized by infrared spectroscopy(FTIR),Raman spectroscopy(Raman),X-ray photoelectron spectroscopy(XPS)and scanning electron microscopy(SEM).Hydrogen(H_(2))was injected to simulate the anode reaction atmosphere,and the potential was controlled at−0.1 V(vs.SCE)to simulate the anode working potential.Open circuit potential(OCP),EIS and polarization curves were used to study the effect of H_(2) on the corrosion performance of bipolar plates.The results indicated that FTIR showed benzene ring,quinone ring,P==O and—COOH stretching vibration,Raman showed doped semi-quinone radical C—N+stretching vibration,and XPS showed that PANI film contained C,N,O and P elements.The corrosion current density of the polarization curve increased in order of H_(2)>N_(2)>O_(2)(DO),and the radius of the EIS capacitive reactance arc decreased in order of H_(2)<N_(2)<O_(2)(DO).The H_(2) environment caused the OCP of PANI/316 L SS system to drop by 0.06 V,the charge transfer resistance(Rct)value to drop by 55Ω/cm^(2),and the self-corrosion potential to drop by about 0.3 V.It is concluded that PANI has an intermediate oxidation state structure.(CH_(3)CH_(2))_(2)PO_(4)−and HOOC—COO−are co-doped in PANI as“counter anions”.Under the PEMFC anode working potential,H_(2) has significant effect on the corrosion resistance of PANI/316 L SS.H_(2) results in the reduction of PANI and the ratio of the sum of—N+==and—N+H—to the total N atom content(N+/N value)decreases by 1.4%,which leads to the de-doping of the“counter anions”in the PANI molecular chains,and the decrease of the corrosion resistance of PANI/316 L SS system.
作者
杨佳宇
周婉秋
刘晓安
辛士刚
康艳红
孙秋菊
YANG Jia-yu;ZHOU Wan-qiu;LIU Xiao-an;XIN Shi-gang;KANG Yan-hong;SUN Qiu-ju(College of Chemistry and Chemical Engineering,Shenyang Normal University,Shenyang 110034,China)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2022年第2期295-305,共11页
Surface Technology
基金
辽宁省教育厅重点实验室基础研究项目(LZ2015066)。
关键词
聚苯胺
不锈钢双极板
离子液体
循环伏安
氢气
耐蚀性
polyaniline
stainless steel bipolar plate
ionic liquid
cyclic voltammetry
hydrogen
corrosion resistance
