Low temperature butane sensing using catalytic nano-crystalline lanthanum ferrite sensing element

Abstract

Highly sensitive, low temperature butane sensing characteristics are reported for nano-crystalline lanthanum iron oxide sensor. The improved butane sensing characteristics of these sensors are explained to be due to their efficient catalytic nature toward butane oxidation. Through infra-red spectroscopy in conjunction with X-ray photoelectron spectroscopy analysis we have demonstrated that the sensor catalytic activity is due to the presence of surface adsorbed oxygen species and hydroxyl ions. The desorbed water and oxygen molecules (originate from the surface adsorbed oxygen and hydroxyl group), initiate the catalytic oxidative dehydrogenation of butane at an operating temperature as low as 250°C. We have also investigated the hydrogen, carbon monoxide and methane sensing performance of lanthanum ferrite sensors. The sensor found to be cross-sensitive to these gases. Thus, the selectivity coefficients for lanthanum ferrite butane sensors were estimated to be 1.67 and 4.67 for 50ppm hydrogen and carbon monoxide sensing respectively. We have reported that first Fourier transform in conjunction with principal component analysis is fruitful to address the cross-sensitivity of nano-crystalline lanthanum ferrite sensor toward butane, hydrogen and carbon monoxide sensing.