Mechanism of NOx Sensing by the Variation of Conductivity of La2CuO4 (特集 環境ガスセンサ)
Mechanism of NOx Sensing by the Variation of Conductivity of La2CuO4 (特集 環境ガスセンサ)
复制标题
通过 La2CuO4 电导率变化进行 NOx 传感的机制（特色：环境气体传感器）
DOI：
10.1541/ieejsmas.118.161
复制
发表时间：
1998
期刊：
影响因子：
--
通讯作者：
H. Tagawa
中科院分区：
文献类型：
--
作者：
J. Mizusaki;M. Hasei;Y. Yonemura;H. Ohama;H. Tagawa
为了弄清楚在氧气气氛中具有少量NOx（x=1，2）的La 2CuO 4的电导率变化的机理，在773- 1023 K的温度下对NOx-O2-N2气体混合物流中的La 2CuO 4的电导率进行测量，并通过氧化锆传感器分析出口气体。分析了氧化锆传感器的电导率和电动势与P（NOx）的关系。P（O2）和T.当NO_2作用于La_2CuO_4上时，发生了NO_2 →NO+（1/2）O_2的催化反应。在催化反应过程中，过量的氧被认为是掺入到La 2CuO 4中。在稳态下。La_2CuO_4中的氧势远高于气相中的氧势。导致La 2CuO 4的p型导电增加。通过数值计算La_2CuO_4中氧势增强与P（NO_2）和T的关系，明确了La_2CuO_4型NO_2传感器的检测限与气相P（O_2）和T的关系。在所研究的条件下，NO对La_2CuO_4导电性的降低作用很小。从催化反应动力学角度探讨了其原因，为提高La 2CuO 4的NO效果指明了方向。
In order to make clear the mechanism of the variation in the conductivity of La2CuO4 with a small amount of NOx (x=1, 2) in oxygen atmosphere, measurements were made on the conductivity of La2CuO4 in the stream of NOx-02-N2 gas mixtures at temperatures 773-1023K and the outlet gas was analyzed by a zirconia sensor. The conductivity and the EMF of the zirconia sensor were analyzed in relation to P(NOx). P(O2) and T. When NO2 was applied to La2CuO4, catalytic reaction of NO2→NO+(1/2)O2 was found to take place. In the catalytic reaction process, excess oxygen was considered to be incorporated into La2CuO4. Under the steady state. the oxygen potential in La2CuO4 was kept much higher than that in the gas phase. resulting in the increase in the p-type conduction of La2CuO4. Numerical calculations were made for the oxygen potential enhanced in La2CuO4 as a function of P(NO2) and T to make clear the detection limits of La2CuO4-type NO2 sensors in relation to the gas phase P(O2) and T. Under the condition studied, NO affects very little to reduce the conductivity of La2CuO4. The reason was discussed based on the catalytic reaction kinetics to show the direction to enhance the NO effect in La2CuO4.