新型固体电解质基氮氧化物传感器的制备与性能研究

氮氧化物(NO_x,NO+NO₂)是我国首要的气体污染源之一，其对自然环境和人类健康均造成了严重的威胁，因此开发原位检测NO_x的高效检测设备势在必行。NO_x的排放源主要为工业废气和汽车尾气，其气体温度较高、成分比较复杂，而固体电解质基气体传感器可以实现在高温下对NO_x的高选择性、高灵敏度检测。本研究以Co₃O₄/Cr₂O₃/YSZ的复合材料为敏感电极，以YSZ为固体电解质构建了阻抗型NO_x传感器。采用XRD、SEM和EDX对传感器进行了表征，并系统研究了传感器在高温下对NO的敏感特性。结果表明：Co₃O₄/Cr₂O₃/YSZ敏感电极材料呈颗粒状，粒径约为200 nm,并且敏感电极以疏松多孔的状态覆盖在电解质表面，有利于气体的扩散和传质。传感器对NO_x具有良好的响应...

Preparation and properties study of a novel NOx sensor based on solid electrolyte

As a major gas pollution source in our country, the NOx poses a serious threat to the natural environment and human health. Therefore, it is necessary to develop high-efficiency detection equipment for the in-situ detection of NOx . The emission sources of NOx are mainly industrial exhaust gas and automobile exhaust gas. The gas temperature is relatively high and the composition is relatively complicated. The solid electrolyte-based gas sensor can realize high selectivity and high sensitivity detection of NOx at high temperature. In this study, a Co3O4 / Cr2O3 / YSZ composite material is used as the sensing electrode and YSZ is used as the solid electrolyte to prepare the impedance metric NOx sensor. The sensor is characterized by XRD, SEM and EDX, and the NOx sensing performance at high temperature is systematically studied. Results show that the Co3O4 / Cr2O3 / YSZ sensing electrode with about 200 nm particle size has a high specific surface area due to the loose and porous structure, which is conducive to gas diffusion and mass transfer. The sensor shows a good response-recovery characteristic to NOx, and the O2 concentration has little influence on the sensor. In addition, the sensor shows good reproducibility, stability, and selectivity. To further apply the sensor for the in-situ detection of NOx under high temperature, a novel self-heated sensor is proposed. The sensor shows good sensitivity characteristics, and the concentration detection range is 10×10 -6 ~ 1 500×10 -6 . In addition, the self-heating sensor shows good reproducibility. This study provides a new idea for the in-situ detection of NOx gas at high temperature.