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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 m A;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 of NOx detection in engine exhaust, and the gas sensing electrode material with NO decomposition activity is the key material in NOx sensor. In this paper, the effects of YSZ doping amount and Pt / Rh ratio on the morphology and voltammetry of Pt-Rh-YSZ gas sensing electrode were studied. Electrode samples with different powder ratios were prepared and characterized by scanning electron microscopy Self-made experimental devices were observed and tested for their electrochemical properties in morphology and simulated atmosphere. The experimental results show that the addition of YSZ powder can significantly improve the co-firing compatibility of the Pt-Rh electrode and the substrate, and can enrich the three-phase interface structure of the electrode at the microscopic scale. When the YSZ content exceeds 12% The structure of complex pores is reduced; the cathode peak appears at 700 ℃ for each electrode, the maximum peak current is 11.29 m A; Rh powder can increase the layered structure at a more micro scale and increase the electrode activity; Pt / Rh ratio Affect the electrode activity, the different diameter of the Pt and Rh mass ratio closer to 1: 1, the electrode activity is stronger.