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 PtCeO2 NFs based sensor was investigated in pure N-2 and different gas mixtures (O-2, CO, CO2, NO, SO2, and C3H8 balanced by N-2) 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 O-2, CO2, NO and SO2(balanced with N-2) 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. (C) 2013 Elsevier B. V. All rights reserved.