| 摘要 |
PURPOSE:To obtain an element which is highly sensitive especially to H2 gas and capable of detecting H2 gas by distinguishing it from other CO, hydrocarbon gas, etc. through such an arrangement wherein at first, a carrier such as Al2O3, etc. is caused to securely hold a catalyst including Pd, and a catalytic layer holding Ag is formed on a gas sensitive body composed on an insulating substrate. CONSTITUTION:A gas sensitive element is composed by such method that a pair of comb type electrodes 2 are formed on an insulation substrate such as Al2O3 etc., and a heater 3 is provided on the back, and a thin film of SnO2 or that including a proper amount of Nb, Sb is formed on the electrodes 2 as a gas sensitive body 4 and a catalytic layer 5 is formed on the sensitive body 4. This catalytic layer 5 is formed on the sensitive body 4. This catalytic layer 5 is formed by such method that at first carrier particles to be selected from Al2O3, SiO2 and ZrO2 are caused to hold Pd and Pt, and then they are immersed in a solution including Ag<+> and calcined, and the immersion and calcination of carrier particles are repeated several times, and the paste of carriers holding Pd and Ag is coated on the sensitive body 4 and a catalytic layer is formed by calcining the sensitive body 4. By this method, a gas sensitive element which is highly sensitive especially to H2 gas can be obtained. |
