阳极反应气氛氢气对聚苯胺/不锈钢耐蚀性的影响

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...

Effects of Hydrogen of Anode Reaction Atmosphere on Corrosion Resistance of Polyaniline/Stainless Steel

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(H₂)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 H₂ 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 H₂>N₂>O₂(DO),and the radius of the EIS capacitive reactance arc decreased in order of H₂22(DO).The H₂ 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 55?/cm²,and the self-corrosion potential to drop by about 0.3 V.It is concluded that PANI has an intermediate oxidation state structure.(CH₃CH₂)₂PO₄?and HOOC—COO?are co-doped in PANI as“counter anions”.Under the PEMFC anode working potential,H₂ has significant effect on the corrosion resistance of PANI/316 L SS.H₂ 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.