Pt-CeO2 nanofibers based high-frequency impedancemetric gas sensor for selective CO and C3H8 detection in high-temperature harsh environment

High-temperature gas sensors are highly demanded to improve the combustion efficiency and reduce the emission of pollutant. In this study, Pt-CeO2 nanofibers (Pt-CeO2 NFs) were prepared using a facile two-step synthetic route (electrospinning followed by calcination). The impedance spectroscopy of the Pt-CeO2 NFs based sensor was investigated in pure N2 and different gas mixtures (O2, CO, CO2, NO, SO2, and C3H8 balanced by N2) with various concentrations at 800 °C. For the first time, the sensor without solid electrolyte was operated at high frequency (100 kHz), so that the sensor response towards O2, CO2, NO and SO2 (balanced with N2) was completely eliminated and strong reducing gases (e.g., CO and C3H8) can be selectively detected with good sensitivity, suggesting that high-frequency impedancemetric technique is a promising approach to improve the selectivity of high-temperature harsh environment gas sensors when operated at an appropriate frequency.