Study on the dispersion of the W ions in the inner surface of γ-Al2O3

• 1、Physics School,Wuhan University

Abstract：A series of the tungsten oxide supported on the porous alumina samples, loaded with different content, heated at different temperatures for different times respectively, prepared by both mechanical mixing and impregnation methods, were studied by positron annihilation spectroscopy, X-ray diffraction (XRD), Differential Thermal Analysis & Thermal Gravimeter (DTA/TG) and X-ray Photoelectron Spectrum (XPS) to show the dispersion of the tungsten ion in the inner surface of the γ-Al2O3. The experiment results indicated the micro dispersion mechanism of the tungsten ion into porous material. And they also showed that in the mechanical mixing method, little of tungsten ion could disperse, grinding was an important action for the dispersion, and in the impregnation method, tungsten ions were into the active center first, and then laid on the non-active areas when over 10% in content, the maximum amount of the mono-layer was 18.5%(in mass fraction of WO3). When heated over 400℃, the tungsten could interact with support, one hour heating was enough for the dispersion of the tungsten ions.

Keywords： Radiation physics impregnation mechanical mixing tungsten oxide dispersion positron annihilation spectroscopy