Design and development of compact, high-performance NOx sensors for preservation of environment

目前研究的目标是对具有保护环境目标的新型高性能氮氧化物传感器的开发。基于离子导体或氧化物半导体的四种固态氮氧化物传感器的固态氮氧化物传感器在这里提出并在这里测试了它们的传感特性。（1） The stabilized zirconia-based electrochemical devices using the oxide sensing electrodes were tested for NOx sensing properties at high temperature。在测试了许多金属氧化物时，发现CdCr 2 O 4或WO 3在500-700℃下给予NO和NO的最佳感应特性。该装置的电磁场反应是线性的，对NOx浓度的逻辑。（2）使用氧化物电极进行选择性淀粉检测在高温下NO的稳定的氧化锆基器件。CdCr 2 O 4附着的管状装置显示出对NO2在500和550 ° C以上的快速和选择性反应，如果传感电极的潜力在+ 100 mV与参考Pt电极的极化。90%的回应 ... More 到100 ppm的分水岭时间不只是短暂的。500 ° C以下20秒目前的反应与0 - 200 ppm范围内的无浓度密切相关。（3） A new solid-state amperometric sensor for NO2 was fabricated by combining an NaイイD1+イエD1 conductor （NASICON） based device with an NaNO2 layer deposited on the counter electrode。With the sensing electrode polarized at - 150 mV relative to the reference Au electrode at 150？， the electric current flowing through the device under exposure to NO2 was linear to the NO2 concentration in the range from 10 ppb to 1 ppm。（4）对半导体氧化物的搜索被携带到设计一个传感器选择性的NO超过NO2。Bi 2 O3是非常选择性的，因为在各种氧化物测试中不是非常敏感的，而NIO被证明是Bi 2 O3增强对不敏感性的最有效的促进剂。传感器元件使用5重量% NiO-Bi 2 O3显示出相当好的传感性能，在敏感性、选择性超过NO2和响应率为300℃时0 - 400 ppm的NO范围内。Less（低）

The purpose of the present study is the development of new type high-performance NOx sensors with the aim of preservation of environment. Four types of solid-state NOx sensors based on ionic conductors or oxide semiconductors were proposed here and their sensing properties were examined. (1) The stabilized zirconia-based electrochemical devices using the oxide sensing electrodes were tested for NOx sensing properties at high temperature. Among the many metal oxides examined, CdCr2O4 or WO3 was found to give the best sensing properties to NO and NO2 at 500-700℃. The EMF response of the device was linear to the logarithm of NOx concentration. (2) The stabilized zirconia-based devices using oxide electrode for selective amperometric detection of NO at high temperature. The CdCr2O4-attached tubular device showed quick and selective response to NO over NO2 at 500 and 550℃, if the potential of sensing electrode was polarized properly at + 100 mV vs. the reference Pt electrode. The 90% respon … More se time of the divide to 100 ppm NO was as short as ca. 20 s at 500℃. The current response was well correlated to the NO concentration in the range of 0 - 200 ppm. (3) A new solid-state amperometric sensor for NO2 was fabricated by combining an NaィイD1+ィエD1 conductor (NASICON) based device with an NaNO2 layer deposited on the counter electrode. With the sensing electrode polarized at - 150 mV relative to the reference Au electrode at 150℃, the electric current flowing through the device under exposure to NO2 was linear to the NO2 concentration in the range from 10 ppb to 1 ppm. (4) A search for semiconducting oxides was carried out to design a sensor selective to NO over NO2. Bi2O3 was very selective to NO through not very sensitive among the various oxides examined, and NiO was proved to be the most effective promoter to Bi2O3 for enhancing NO sensitivity. The sensor element using 5wt%NiO-Bi2O3 showed fairly good sensing properties to NO in the range of 0 - 400 ppm in sensitivity, selectivity over NO2, and response rate, at 300℃. Less