Microstructural and Electrical Characterization of Novel Porous ZrO2-based NOx Sensors

非技术描述：废气传感器在柴油卡车和轿车中起着监测排放和调节发动机运行的关键作用。美国最近的排放标准对柴油车的氮氧化物排放提出了更严格的标准，以进一步限制和减少空气污染物。目前的传感器无法测量到达到环境保护局设定的2015年Tier 2，Bin 8排放标准的氮氧化物水平。这一缺点产生了对具有更高灵敏度和精度的柴油废气传感器的需求。本项目主要研究由新型多孔陶瓷结构组成的气体传感器。本项目的研究活动提供了对传感器微结构如何影响传感器的电学性能、动力学反应和电化学响应的基本了解。这方面的知识很重要，因为它直接影响传感器的灵敏度、选择性和准确性。该项目通过参与研究结果的数据收集、分析和报告，为本科生和研究生提供研究经验，这对他们的大学教育有很大帮助。外展活动的范围从实验室研究体验到与小学儿童的实践课后活动。技术细节：新的柴油排放监管标准为污染物水平设定了更严格的门槛；因此，需要具有更高灵敏度、选择性和准确性的氮氧化物传感器。目前的传感器能够测量浓度低至百万分之十的氮氧化物排放，这将不能满足新的标准。新型多孔电解液气体传感器是替代传统柴油机排气传感器的一种很有前途的传感器。在这个项目中，我们研究了在各种工作条件下，采用新型多孔氧化锆电解液和致密的钙钛矿型传感电极的传感器的电学响应。本课程的目的是对由电解液和传感电极的微观结构属性决定的传感行为有一个基本的了解。生成的数据有助于确定影响传感器灵敏度、选择性和准确度的动力学反应机理、温度依赖性和操作条件。外展活动的范围从本科生和研究生的实验室研究体验，到与小学适龄儿童的实践课后活动。

NON-TECHNICAL DESCRIPTION: Exhaust gas sensors play a critical role in monitoring emissions and regulating engine operation in diesel trucks and cars. Recent emission standards for the United States places more stringent standards on nitrogen oxide emissions from diesel vehicles in order to further limit and reduce air pollutants. Current sensors are not capable of measuring nitrogen oxides at levels that will satisfy 2015 Tier 2, Bin 8 emission standards set by the Environmental Protection Agency. This shortcoming creates a need for diesel exhaust gas sensors with greater sensitivity and accuracy. This project focuses on gas sensors composed of a novel porous ceramic architecture. The research activities in this project are providing a fundamental understanding of how the sensor microstructure affects the electrical properties, kinetic reactions, and electrochemical response of the sensor. This knowledge is important as it has a direct impact on sensor sensitivity, selectivity and accuracy. This project provides research experiences for undergraduate and graduate students through participation in the data collection, analysis, and reporting of research results, which greatly contributes to their university education. The outreach activities range from laboratory research experiences to hands-on afterschool activities with elementary age children. TECHNICAL DETAILS: New regulatory standards for diesel emissions have established more stringent thresholds for pollutant levels; thereby, creating a need for nitrogen oxide sensors with greater sensitivity, selectivity and accuracy. Current sensors are capable of measuring nitrogen oxide emissions at concentrations down to approximately 10 parts per million, which will not satisfy new standards. Novel porous electrolyte based gas sensors are a promising alternative to conventional diesel exhaust sensors. In this project, the electrical response of sensors with a novel porous zirconia electrolyte and dense perovskite sensing electrodes are being studied over a range of operating conditions. The aim is to acquire fundamental understanding of sensing behavior that is governed by the microstructural properties of the electrolyte and sensing electrode. The data generated is useful for determining kinetic reaction mechanisms, temperature dependence, and operating conditions effecting sensor sensitivity, selectivity and accuracy. The outreach activities range from laboratory research experiences for undergraduate and graduate students, to hands-on afterschool activities with elementary age children.