Abstract

The monolayer dispersion of tungsten oxide on the surface of anatase has been studied by BET surface area measurements, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transformation infrared spectroscopy (FTIR) and Raman spectroscopy. The results reveal that for the anatase supported tungsten oxide samples, tungsten oxide species can be highly dispersed on the surface of the support and the dispersion state of tungsten oxide species is strongly related to the loading amount of tungsten oxide. In addition, it is found that tungsten oxide can retard the anatase–rutile transformation. When the loading of WO₃ is below its monolayer dispersion capacity, the onset temperature of the anatase–rutile transformation is strongly affected by the dispersed tungsten oxide. Crystalline WO₃ appears when the WO₃ loading is higher than the monolayer dispersion capacity but has little effect on the phase transformation of the samples.