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

设计和开发用于保护环境的紧凑型高性能氮氧化物传感器

基本信息

批准号：
09450320
负责人：
MIURA Norio
金额：
$ 9.09万
依托单位：
KYUSHU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

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

本研究的目的是开发新型高性能氮氧化物传感器，以保护环境为目的，提出了四种基于离子导体或氧化物半导体的固态氮氧化物传感器，并检查了它们的传感特性。 (1) 使用氧化物传感电极的稳定氧化锆基电化学装置在高温下测试了 NOx 传感性能，在所检查的许多金属氧化物中，发现 CdCr2O4 或 WO3 具有最佳的传感性能。 500-700℃下NO和NO2的EMF响应与NOx浓度的对数呈线性关系。 (2)使用氧化物电极对高温下NO进行选择性安培检测的稳定氧化锆装置。如果传感电极的电位正确极化为 + 100 mV，则管状装置在 500 和 550℃ 下对 NO 表现出比 NO2 更快且选择性的响应与参比 Pt 电极相比，在 500℃ 时，对 100 ppm NO 的 90% 响应时间短至约 20 秒。在 0 - 范围内，电流响应与 NO 浓度密切相关。 200 ppm (3) 通过将基于 NaiD1+D1 导体 (NASICON) 的设备与NaNO2 层沉积在对电极上，在 150℃ 下，传感电极相对于参比 Au 电极极化为 - 150 mV，暴露于 NO2 时流过器件的电流在 10 ppb 范围内与 NO2 浓度呈线性关系。 (4) 对半导体氧化物进行了研究，设计了一种对 NO 的选择性高于 NO2 的传感器，Bi2O3 对 NO 的选择性非常高，但在各种氧化物中不是很敏感。经检验，NiO 被证明是 Bi2O3 增强 NO 灵敏度最有效的促进剂。使用 5wt%NiO-Bi2O3 的传感器元件在 0 - 400 ppm 范围内对 NO 表现出相当好的传感性能，对 NO2 的选择性、选择性。和响应率，在300℃以下。