Pt-Rh-YSZ气敏电极微观形貌和伏安特性研究  

Microstructure and Volt-Ampere Characteristics of Pt-Rh-YSZ Gas Sensing Electrodes

作　　者：刘高斯 熊晓东 贺昕 陈峤 Liu Gaosi;Xiong Xiaodong;He Xin;Chen Qiao(General Research Institute for Nonferrous Metals, Beijing 100088, China;GRIKIN Advanced Materials Co. , Ltd, Beijing 102200, China)

机构地区：[1]北京有色金属研究总院,北京100088 [2]有研亿金新材料有限公司,北京102200

出　　处：《稀有金属》2017年第12期1339-1346,共8页Chinese Journal of Rare Metals

基　　金：十二五国家科技支撑计划项目(2012BAE06B07)资助

摘　　要：NOx传感器是发动机尾气中氮氧化合物检测的关键器件,而具有NO分解活性的气敏电极材料则是NOx传感器中的关键材料。本文对YSZ掺杂量与Pt/Rh配比对Pt-Rh-YSZ气敏电极的微观形貌和伏安特性的影响进行了研究,通过制备不同粉体配比的电极样品,利用扫描电镜(SEM)和自制实验装置对其形貌和模拟气氛中的电化学性能进行了观察和测试。实验结果表明,YSZ粉末的加入能够明显改善Pt-Rh电极与基体的共烧匹配性,且能在微观尺度上使电极的三相界面结构更丰富,当YSZ含量超过12%时,电极表面的复杂孔洞结构减少;各电极在700℃出现阴极峰,最大峰值电流为11.29 mA;Rh粉的加入能在更微观的尺度上增加层状结构,并增大电极的活性;Pt/Rh配比影响电极活性,不同粒径的Pt和Rh质量比越接近1∶1,电极的活性越强。NOx sensor is the key component for nitrogen oxides detection in engine exhaust. The gas sensitive electrode material with NO decomposition activity is the key material in NOx sensor. In this paper, the effect of YSZ doping amount and ratio of Pt/Rh on Pt- Rh-YSZ microstructure and volt-ampere characteristics of gas sensitive electrode was studied. Electrode samples with different powder ratios were prepared, the morphology was observed by scanning electron microscope （SEM） and the electrochemical performance in simulated atmosphere was tested with self-made device. The results showed that the addition of YSZ powder could significantly improve the co-firing matching of Pt-Rh electrode and matrix, and made three phase interface structure of electrode more abundant in micro scale. When the mass content was more than 12% , the complex hole structure in electrodes decreased. The cathodic peak of each e- lectrode appeared at 700 ℃ and the maximum peak current was 11.29 mA. The addition of Rh powder could increase the layered structure in micro-scale and increase the electrode activity. The activity of the electrode was influenced by the ratio of Pt/Rh. When the mass ratio of Pt/Rh was closer to 1 ： 1, the activity of the electrode was stronger.

关 键 词：Pt—Rh—YSZ 气敏电极 伏安特性 微观形貌 Pt/Rh配比 

分 类 号：TG146.3[一般工业技术—材料科学与工程]