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

非技术描述：废气传感器在监测柴油卡车和汽车的排放和调节发动机运行方面发挥着关键作用。美国最新的废气排放标准对柴油车辆的氮氧化物排放量提出更严格的标准，以进一步限制和减少空气污染物。目前的传感器无法测量符合美国环境保护署（Environmental Protection Agency）制定的2015 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准确度的柴油机废气传感器的需求。该项目的重点是一种新型的多孔陶瓷结构组成的气体传感器。在这个项目中的研究活动提供了传感器的微结构如何影响传感器的电性能，动力学反应和电化学响应的基本理解。这些知识非常重要，因为它直接影响传感器的灵敏度、选择性和准确性。该项目通过参与数据收集、分析和研究结果报告，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贡献。外展活动范围从实验室研究经验到小学年龄儿童的课外实践活动。技术规格：柴油机排放的新监管标准为污染物水平建立了更严格的阈值;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约百万分之十的氮氧化物排放，这将不符合新标准。新型多孔电解质基气体传感器是传统柴油机排气传感器的一种很有前途的替代品。在该项目中，正在研究具有新型多孔氧化锆电解质和致密钙钛矿传感电极的传感器在一系列操作条件下的电响应。其目的是获得由电解质和传感电极的微观结构特性决定的传感行为的基本理解。生成的数据可用于确定动力学反应机制、温度依赖性和影响传感器灵敏度、选择性和准确性的操作条件。外展活动范围从本科生和研究生的实验室研究经验，到小学年龄儿童的课外实践活动。

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.