title: CO Sensing Performance of a Micro Thermoelectric Gas Sensor with AuPtPd/SnO₂ Catalyst and Effects of a Double Catalyst Structure with Pt/α-Al₂O₃.
abstract: The CO sensing properties of a micro thermoelectric gas sensor (micro-TGS) with a double AuPtPd/SnO₂ and Pt/α-Al₂O₃ catalyst were investigated. While several nanometer sized Pt and Pd particles were uniformly dispersed on SnO₂, the Au particles were aggregated as particles measuring >10 nm in diameter. In situ diffuse reflectance Fourier transform Infrared spectroscopy (DRIFT) analysis of the catalyst showed a CO adsorption peak on Pt and Pd, but no clear peak corresponding to the interaction between CO and Au was detected. Up to 200 °C, CO combustion was more temperature dependent than that of H₂, while H₂ combustion was activated by repeated exposure to H₂ gas during the periodic gas test. Selective CO sensing of the micro-TGS against H₂ was attempted using a double catalyst structure with 0.3-30 wt% Pt/α-Al₂O₃ as a counterpart combustion catalyst. The sensor output of the micro-TGS decreased with increasing Pt content in the Pt/α-Al₂O₃ catalyst, by cancelling out the combustion heat from the AuPtPd/SnO₂ catalyst. In addition, the AuPtPd/SnO₂ and 0.3 wt% Pt/α-Al₂O₃ double catalyst sensor showed good and selective CO detection. We therefore demonstrated that our micro-TGS with double catalyst structure is useful for controlling the gas selectivity of CO against H₂.
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST), 2266-98 Shimo-Shidami, Moriyama-ku, Nagoya 463-8560, Japan. goto@sanken.osaka-u.ac.jp.
authors.forename: Tomoyo
authors.initials: T
authors.lastname: Goto
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST), 2266-98 Shimo-Shidami, Moriyama-ku, Nagoya 463-8560, Japan. itoh-toshio@aist.go.jp.
authors.forename: Toshio
authors.initials: T
authors.lastname: Itoh
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST), 2266-98 Shimo-Shidami, Moriyama-ku, Nagoya 463-8560, Japan. t-akamatsu@aist.go.jp.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Akamatsu
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST), 2266-98 Shimo-Shidami, Moriyama-ku, Nagoya 463-8560, Japan. w.shin@aist.go.jp.
authors.forename: Woosuck
authors.initials: W
authors.lastname: Shin
mesh_terms: D002248:Carbon Monoxide / Q000032:analysis*; D002623:Chemistry Techniques, Analytical / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D006358:Hot Temperature; D006859:Hydrogen / Q000032:analysis; D019216:Metals, Heavy / Q000737:chemistry*; D008697:Methane / Q000032:analysis; D017971:Tin Compounds / Q000737:chemistry*
chemical_list: D019216:Metals, Heavy; D017971:Tin Compounds; D002248:Carbon Monoxide; D006859:Hydrogen; C045358:stannic oxide; D008697:Methane
keywords: CO oxidation; combustion catalyst; gas selectivity; noble metals; thermoelectric gas sensor