CO Sensing Property of Transition Metal Oxide-Loaded SnO2 in a Reducing Atmosphere

CO sensing properties of various transition metal oxide-loaded SnO2 sensors were investigated in a reducing atmosphere such as wet H2 gas. Among transition metal oxide-loaded SnO2 sensors used in the present study, CuO-loaded SnO2 sensor exhibited the highest sensor response to 1% CO in wet 50% H2 at around 150°C, while it showed no sensor response in dry 50% H2. From X-ray diffraction (XRD) analysis, CuO was reduced to metallic Cu in a reducing atmosphere at above 150°C. H2-temperature-programmed reduction (H2-TPR) and diffuse reflectance Fourier transform infrared (DRIFT-IR) spectroscopy measurements were carried out to discuss the sensor response mechanism.