高电位下PEMFC阴极催化层Pt对碳腐蚀的影响  

Effect of Pt on carbon corrosion in PEMFC cathode catalyst layer at high constant potential

作　　者：刘明俊 周芬[1,2,3] 朱振 黄鹏涛[1,2] 姚志鹏 潘牧[1,2,3] LIU Mingjun;ZHOU Fen;ZHU Zhen;HUANG Pengtao;YAO Zhipeng;PAN Mu(State Key Laboratory of Advanced Technology for Materials Synthesis and Processing,Wuhan University of Technology,Wuhan Hubei 430070,China;Hubei Key Laboratory of Fuel Cells,Wuhan University of Technology,Wuhan Hubei 430070,China;Foshan Xianhu Laboratory of Advanced Energy Science and Technology Guangdong Laboratory,Foshan Guangdong 528200,China)

机构地区：[1]武汉理工大学材料复合新技术国家重点实验室,湖北武汉430070 [2]武汉理工大学燃料电池湖北省重点实验室,湖北武汉430070 [3]先进能源科学与技术广东省实验室佛山仙湖实验室,广东佛山528200

出　　处：《电源技术》2024年第6期1003-1010,共8页Chinese Journal of Power Sources

基　　金：国家自然科学基金(22209026)。

摘　　要：结合非色散红外光谱(NDIR)和电化学表征的方法研究了质子交换膜燃料电池阴极催化层在0.8 V恒电位下,碳腐蚀的变化规律及其对Pt氧化过程的依赖性。研究发现0.8 V恒电位下,Pt会导致碳载体的腐蚀更加剧烈。运行100 h后,Pt/C电极的碳损失质量达到8.7%,是纯碳电极的3.5倍。Pt/C电极的碳腐蚀规律可以分为三个阶段,第一阶段呈对数增长,第三阶段呈线性增长,中间存在混合增长区。而Pt氧化物累积量分析表明Pt的氧化呈现出两段对数关系,且中间存在一个过渡区,这解释了碳腐蚀的三段规律。活跃的Pt-OH催化碳腐蚀,并快速转化成PtO_(x)等惰性氧化物,大幅降低对碳腐蚀的促进作用,当Pt-OH含量稳定后,碳腐蚀速率达到稳态。电位阶跃工况下,Pt氧化物增长速度明显降低,碳载体质量损失达到了15.55%,几乎是恒电位工况的2倍,表明控制Pt氧化物累积速度会加速碳载体的腐蚀。The variation of carbon corrosion and its dependence on Pt oxidation process in the cathode catalyst layer of PEMFC at 0.8 V constant potential were studied by non-dispersive infrared spectroscopy(NDIR)and electrochemical characterization.It’s found that Pt leads to more severe corrosion of carbon carrier at 0.8 V constant potential.After 100 hours,the mass loss of carbon in the Pt/C electrode reaches 8.7%,which is 3.5 times that of the pure carbon electrode.The carbon corrosion of Pt/C electrode can be divided into three stages.The first stage shows the logarithmic growth,while the third stage follows the linear growth,and there is a mixed growth zone in the middle.The analysis of Pt oxide accumulation presents that the oxidation of Pt exhibits a two-stage logarithmic relationship,and there is a transition zone in the middle,which explains the three-stage law of carbon corrosion.The active Pt-OH catalyzes the carbon corrosion of Pt/C electrode and rapidly converts into the inert oxides such as PtO_(x),which greatly reduces the catalytic effect on carbon corrosion.When the Pt-OH content gets equilibrium,the carbon corrosion rate comes to a steady state.Under the step potential condition,the growth rate of Pt oxide obviously reduces,but the mass loss of carbon is up to 15.55%,almost twice that under constant potential condition,indicating that controlling the accumulation rate of Pt oxide could accelerate the corrosion of carbon carrier.

关 键 词：碳载体腐蚀 0.8 V恒电位 PT催化剂 Pt氧化物 

分 类 号：TM911.4[电气工程—电力电子与电力传动]