| 摘要 |
PURPOSE:To obtain the gas detecting element suitable for detecting low concentration gas such as Freon gas, by forming a catalyst layer, wherein a noble metal having a specified composition is supported on a support comprising Al2O3, SiO2 and the like, on the surface of a sensitive body formed by a metal oxide semiconductor. CONSTITUTION:The sensitive body is formed by providing the metal oxide semiconductor layer 3 on the surface of a tubular insulating substrate 1, on which a pair of electrodes 2 are preliminarily provided. The catalyst layer, wherein V and at least one kind of noble metal selected among Rh, Pd, Pt, and Au are supported by a support comprising Al2O3, SiO2, or SiO2-Al2O3, is provided on the surface of the layer 3. The ratio of the supporting amount of V to the support is specified in the range of 0.1-50wt%, preferably 0.5-15wt%, and the g atomic ratio of the supporting amount of the noble metal to V is specified in the range of 0.005-0.5, preferably 0.1-0.4. In this way, the detecting element, which has excellent sensitivity to Freon gas and the like suitable for the low concentration gas can be obtained. |
