| 摘要 |
PURPOSE:To obtain the titled detecting element that shows a high sensitivity to the gaseous feron gas, by providing a catalyst layer deposited Pd and P to the silica gel with addition of an acid treatment on the surface of a gas sensor made of a metallic oxide semiconductor. CONSTITUTION:A prescribed amount of PdCl2 aqueous of solution and H3PO4 are added to a prescribed amount of silica gel to obtain a paste, and after impregnating for a certain time under evacuation, the paste is dried, crushed and calcined. In such way, a catalyst which is deposited 0.05-10wt% and 0.05-20 times mol P as much as Pd on the silica gel is obtained. Then such catalyst is immersed in the hydrochloric acid with a heat treatment and then coated on the surface of the gas sensor 3 made of a metallic oxide semiconductor covering over the cylindrical insulated substrate 1 and the electrodes 2 and then calcined at 300-800 deg.C after drying to obtain a catalyst layer 4. Thus the titled detecting element is obtained. |
