面向汽车在线诊断(OBD)的YSZ基混成电位型气体传感器阵列研究

The urgent need for on-board diagnosis (OBD) of automobile, the development of NOx and NH3 sensor arrays based on YSZ and oxide sensing electrodes is of great scientific significance. Currently, in order to meet the harsh application environments, the key scientific issue must be addressed is that how to enhance the sensitivity, selectivity, humidity resistance and stability of the sensor arrays. In this project, to improve the sensitivity and selectivity of the sensor arrays, three-level sensitization strategies are performed by means of designing the novel composite oxides sensing electrode materials, modifying the porous sensing electrode, doping noble metal or composites and fabricating the high effective three phase boundary. Using the methods with inducing the hydrophobic material, changing the operating temperature, the surface modification and treatment of YSZ, and optimizing device sintering and aging conditions to enhance the humidity resistance and stability. The implementation of this project will not noly construct NOx and NH3 sensor arrays for on-board diagnosis, but also provide new technology and strategy for improved sensing performance of the mixed potential type gas sensor. Additionally, striving to expand the scope of sensing material systems and further clarify the sensing mechanism and determine the design of gas sensor.

面向汽车在线诊断（OBD）的急需，构建基于YSZ和氧化物敏感电极的NOx、NH3传感器阵列具有重要的科学意义。目前，如何提升传感器阵列的灵敏度、选择性、耐湿性和稳定性是满足苛刻使用环境必须解决的关键科学难题。本项目通过设计新型复合氧化物敏感电极材料的“材料增感”、对氧化物敏感电极多孔化、贵金属掺杂或金属氧化物复合的“改性增感”和构筑高效三相反应界面所赋予的“界面增感”三级增感策略提升传感器阵列的灵敏度和选择性；通过引入疏水性材料、调控工作温度、YSZ表面修饰与处理以及优化器件烧结和老化条件等方法，改善传感器阵列的耐湿性和稳定性。本项目的实施不仅可以构建实现在复杂环境下对机动车尾气进行在线监控的NOx、NH3传感器阵列，而且能够为提升混成电位型气体传感器的敏感特性提供新技术和新策略。此外，还力争拓展电极材料体系范围、进一步明晰传感机理，确立传感器设计指针。

面向汽车在线诊断（OBD）的急需，构建基于稳定氧化锆（YSZ）和氧化物敏感电极的NOx传感器具有重要的科学意义。本项目通过设计和制备具有良好电化学催化反应活性的CoTiO3复合氧化物敏感电极材料，优化工作温度，采用静电纺丝技术构筑具有纳米网络阵列结构的多孔稳定氧化锆固体电解质，增大三相反应界面面积，构建了高灵敏和高选择的YSZ基混成电位型NO2传感器。在650℃，基于CoTiO3敏感电极的传感器对100 ppm NO2 表现出最高的响应值，为130 mV。同时传感器对NO2具有较低的检测下限(500 ppb)、良好的灵敏度(60 mV/decade)、卓越的选择性和良好的稳定性；以流速为1.5 mL/h，纺丝时间为15 min制作的YSZ基板和NiO敏感电极构建的传感器（S30）对55-500 ppm NO2表现出最高的灵敏度（77.4 mV/decade），是未处理的YSZ基板制作传感器（S00）的2.6倍。在510℃时，S30对100 ppm NO2的响应值可以达到109 mV，与S00相比，增加了约51 mV。此外，该传感器（S30）还表现出快速的响应和恢复速度、良好的重复性、选择性、耐湿性和稳定性。为车载氮氧化物传感系统提供潜在的应用器件。此外，还拓展了其他Ti系复合氧化物、Sn基尖晶石复合氧化物敏感电极材料、进一步明晰了传感机理，研制了面向机动车排气中碳氢化合物和SO2检测的混成电位型传感器以及H2S、VOC等传感器。