Thermoelectric gas sensors (TGS) for microcalorimeters with a CO combustion catalyst were fabricated and tested for the detection of ppm level CO. Two types of CO combustion catalysts containing 3 wt% Au, Pd, and Pt loaded on CoO and Co3O4 were prepared through a colloidal mixing process and integrated on the TGS. The 3 wt% AuPdPt loaded on the CoO and Co 3O4 catalysts exhibited stable CO combustion performance at temperatures as low as 200 C, which is a much lower temperature than that of a previous study using a Au/Co3O4 catalyst. The TGS of 3 wt%(AuPdPt)/CoO catalyst showed better CO selectivity than that of Co 3O4, and could detect CO over a wide concentration range from 1 ppm to 1% (v/v) CO in air, with a gas concentration resolution of 1 ppm CO, signal to noise ratio of 6.8, and CO selectivity against H2 of 1.75.
- CO oxidation
- Thermoelectric gas sensor