Pt clusters supported on WO3 for ethanol detection

A novel sensor material of WO3 supported Pt clusters hybrid material was synthesized, with control over the Pt loading content by simply varying the amount of H2PtCl6 precursor. The as-prepared WO3 supported Pt cluster composites were characterized by means of X-ray diffraction, transmission electron microscope and X-ray photoelectron spectroscopy. TEM images show that the Pt clusters with a fine size of ca. 2 nm are uniformly dispersed on WO3 matrix. Gas sensing tests reveal that the Pt/WO3 hybrid material with a Pt content of 2.36 wt% exhibits the best response towards ethanol detection at an operating temperature of 140 °C. The sensor also possesses fast response and recovery characteristics, good selectivity and stability. The enhanced sensor performance is interpreted in terms of the proper content, uniform dispersion and small size of Pt clusters, which probably have a strong spillover effect and can serve as active sites for sensing reactions and excellent channel for electron transfer in the process of sensing reactions. The electronic interaction between Pt clusters and WO3 support is also believed to contribute to the improved sensor performance.