NOx sensing characteristics of Ba2WO5 to at elevated Temperatures

Abstract

NOx Sensing Characteristics of Ba2WO5 were investigated in an effort to search for a new sensor material operative at high temperatures. Ba2WO5 was prepared from WO3 and BaCo3 and packed and sintered to fabricate disk-type sensor elements. Ba2WO5 exhibits neck-controlled conduction and provides highest sensitivity of 47 and 29 at 500 to 200 ppm NO and 80 ppm NO2 respectively. The samples sintered beyond 800℃. From the response transient to NO and NO2 and NO2(g)＋e→NO2-, and NO(g)+O(abs)+e→NO2- are proposed as possible reactions occurring on the surface of Ba2WO5 in the presence of NO and NO2 gases.