P2GS.26 - Plasma Enhanced Detection Of Methane On Pt/SnO2 Sensors At Low Temperatures

17th International Meeting on Chemical Sensors - IMCS 2018
2018-07-15 - 2018-07-19
Vienna, Austria
P-2 - Gas Sensors
M. Arvari - 1Catalysis and Reaction Engineering Laboratory, Departmentt of Chemical Engineering, University of Tehran, Tehran (Iran), A. Khodadadi, Y. Mortazavi - Nanoelectronics Centre of Excellence, University of Tehran, Tehran (Iran)
817 - 818


In this study, a non-thermal plasma (NTP) corona needle-shape reactor was applied before Pt/SnO2 sensor to detect methane with high responses at low temperatures. 5000 ppm methane in air, by passing through NTP reactor at ambient temperature, have been converted to reactive intermediately including CO. After reaching to the sensor, the responses have been measured at 200-400ºC temperature range. The effects of plasma parameters including the distance between electrodes and electrical power, as well as sensor temperature have been varied. The synthesis of Pt/SnO2 was carried out by precipitation method impregnated with H2PtCl6 to get 1.0 wt% Pt/SnO2. The sample was characterized by XRD, BET and FTIR. Exposure of methane to NTP reactor with 2.5 mm electrode distance by an increase in electrical power to 0.9 W results in 20% conversion. The corresponding parameters at 5 mm interval are 1.4 W and 41%. Without using the plasma, maximum response to CH4 occurs at the high temperature of 400ºC. At electrode distances of 2.5 mm with 0.9 W electrical power and 5mm with 1.4W, the maximum responses has increased 144 and 331 times respectively than the single sensor at 200ºC. This way, very high responses to CH4 at 200ºC has been achieved by Pt/SnO2 gas sensor in the presence of NTP corona needle system.