Pt-CeO_2 nanofibers based high-frequency impedancemetric gas sensor for selective CO and C_3H_8 detection in high-temperature harsh environment

摘要

High-temperature gas sensors are highly demanded to improve the combustion efficiency and reduce the emission of pollutant. In this study, Pt-CeO_2 nanofibers (Pt-CeO_2 NFs) were prepared using a facile two-step synthetic route (electrospinning followed by calcination). The impedance spectroscopy of the Pt-CeO_2 NFs based sensor was investigated in pure N_2 and different gas mixtures (O_2, CO, CO_2, NO, SO_2, and C_3H_8 balanced by N_2) with various concentrations at 800 ℃. For the first time, the sensor without solid electrolyte was operated at high frequency (100 kHz), so that the sensor response towards O_2, CO_2, NO and SO_2 (balanced with N_2) was completely eliminated and strong reducing gases (e.g., CO and C_3H_8) 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.