采用交流阻抗测试技术、循环伏安、计时电流和扫描电镜等实验方法,研究了Pt/YSZ电极烧制温度对其性能的影响.研究表明,随着烧制温度升高,电极过程激活能减小,电极总阻抗和响应时间均先减小后增大.烧制温度小于或等于1100℃时,氧原子大量吸附于Pt电极表面,与铂原子发生位置重排反应而生成Pt氧化物,电极过程激活能为177~230 kJ.mol-1 烧制温度大于1100℃时,电极系统中可能存在的Pt氧化物充分解离,电极过程激活能为107~172 kJ.mol-1.烧制温度为1000~1100℃所制电极总阻抗最小,电荷转移过程响应最快,电极活性最高.
The effects of Pt/YSZ electrode sintering temperature on its characteristics were studied by AC impedance,cyclic voltammetry,chronoamperometry,and SEM observation.The result indicates that as the sintering temperature increases,the activation energy of the electrode process decreases,both the electrode total resistance and response time decrease first and then increase.While the sintering temperature is below or equal 1 100 ℃,a large quantity of oxygen atoms are adsorbed on the Pt electrode surface,Pt oxide will be found due to the site exchange reactions of the adsorbed oxygen atoms and Pt atoms,and the activation energy of the electrode process is from 177 to 230 kJ·mol-1;as the sintering temperature is above 1 100 ℃,Pt oxide probably existed in the electrode system decomposes completely,and the activation energy of the electrode process is from 107 to 172 kJ·mol-1.The electrode sintered at temperatures of 1 000 to 1 100 ℃ has the least total resistance,the shortest response time of charge transfer,and the highest activity.