改性316L不锈钢表面聚苯胺的制备及电化学性能  

Preparation and Electrochemical Performance of Polyaniline Film Formed on Acid-activated Stainless Steel 316L

作　　者：刘明[1] 田颖[1] 傅杰[1] 徐洪峰[1] 

机构地区：[1]大连交通大学环境与化学工程学院,大连116028

出　　处：《高等学校化学学报》2016年第12期2228-2235,共8页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:21106012);辽宁省教育厅基金(批准号:L2014180)资助~~

摘　　要：采用原位氧化技术调整316L不锈钢(SS316L)基体元素Cr和Ni在界面的浓度和分布,形成了Ni和Cr富集改性界面.应用计时电位技术,通过Cr和Ni改性层催化草酸溶液中的苯胺单体在其表面吸附并聚合,在SS316L表面沉积了附着力良好的聚苯胺(PANI)膜.与SS316L相比,表面富Ni-Cr的SS316L在涂覆PANI膜后,在80℃0.5 mol/L H_2SO_4+5 mg/L F^-溶液中阳极和阴极的腐蚀电位分别提高470和500 m V,维钝电流均下降2~3个数量级;在模拟质子交换膜燃料电池运行环境中,经36000 s恒电位极化,其阳极和阴极的腐蚀电流分别下降约1和2个数量级,腐蚀速度分别约为6~9和<5μA/cm^2;在1.4 MPa压力下,聚苯胺膜层与Toray 060碳纸间接触电阻下降约250 mΩ·cm^2.SS316L表面形成富Ni-Cr改性层并涂覆聚苯胺膜后,其耐蚀性和导电性均明显优于原始SS316L,这主要取决于富Ni-Cr改性层的结构、组成和聚苯胺膜的厚度.Ni-Cr enrichment on stainless steel 316L（SS316L） was achieved by adjusting the concentration and distribution of Cr and Ni on the surface of the SS316 L substrate through in situ oxidation processes.Aniline monomers were absorbed and polymerized on the surface of modified SS316 L,and a polyaniline（PANI）/Ni-Cr enriched SS316 L composite was prepared using chronopotentiometry（CP） technique. Under both reducing（anode simulated） and oxidizing（cathode simulated） conditions of proton exchange membrane fuel cell（PEMFC）,the results of potentiodynamic test showed that the PANI coating increased the free corrosion potential of the steel by more than 470 and 500 m V,respectively,with a passivation current density more than 2—3 orders of magnitude lower than that of the bare steel. Under the PEMFC environment,the corrosion currents of the anode and cathod of PANI/Ni-Cr enriched SS316 L electrode were decreased by 1 and 2 orders of magnitude,and corrosion rates of the anode and cathode were about 6—9 μA/cm2 and 5 μA/cm2,respectively. Furthermore,the interface contact resistance between the PANI film and carbon paper was reduced by about 250. 0 mΩ·cm2 at a compaction pressure of 1.4 MPa. Polyaniline/Ni-Cr enriched SS316 L bipolar plate was remarkably more stable in simulated PEMFC environments,and more conducting compared to the bare SS316 L.

关 键 词：Ni-Cr改性层 质子交换膜燃料电池 不锈钢 聚苯胺 双极板 

分 类 号：O646[理学—物理化学]