Micro-multi-gas sensor (micro-MGS) of 3 thermoelectric devices with 3 different combustion catalysts was developed. Using the micro-heater meanders of Pt/Pt-W thin film, the temperature of the Pt/Al2O3, Au/Co3O4 and Pt/Al2O3 catalysts were controlled to be 360, 240 and 140 °C for the selective combustion of CH4, CO and H2, respectively. The gas sensing performance of the micro-TGS for the gas mixture of 0.5-vol.%CH4 + 0.5-vol%CO + 0.5-vol%H2 was been investigated. The Pd/Al2O3 burned all gases and the Au/Co3O4 could burn CO selectively. The Pt/Al2O3 burned H2 and CO by controlling the temperature of the catalyst. The selectivity of this micro-MGS with the Pd/Al2O3, Au/Co3O4 and Pt/Al2O3 catalysts is higher than that of a SnO 2 based thick-film sensor array for H2, CO, CH 4. From the voltage signal from 3 different sensor elements, the micro-MGS could estimate the gas concentration selectively without any gas separation tool.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering