A low temperature catalytic-type combustible gas sensor based on Pt supported zeolite catalyst films

Abstract

In this study, a catalytic-type combustible gas sensor was fabricated by the screen-printing method. Pt supported catalysts (Pt-HZSM5) were prepared by a wet impregnation method using HZSM5 zeolite as support. It was found that Pt-HZSM5 catalysts have a highly catalytic activity to H2 and CO at low temperatures and a selectively and fully combustible was observed at only 150 °C. A good dispersion state of Pt nanoparticles on HZSM5 zeolite particles was beneficial for the catalytic oxidization of CO and H2. However, a high loading amounts lead to a poor dispersion state and a weak catalytic activity. The thick film sensor based on Pt-HZSM5 catalyst was found to be highly sensitive to combustible gas with a good linearity up to 2% and a limitation of detection (LOD) around 50 ppm. Due to the low operation temperature, a highly selectivity was obtained for CO and H2 and no cross-sensitivity to interfering gases such as CH4 and VOCs. It was indicated that the present developed catalytic-type gas sensors could be used for the leakage detection and monitor for H2 and CO with a low power consumption and a good selectivity.