In-situ XAFS study for calcination process of Cr catalyst supported on γ-Al2O3 and SiO2

16th International Conference on X-ray Absorption Fine Structure

Watanabe, T.^1 ; Ikeda, K.^1 ; Katayama, M.^1 ; Inada, Y.^1

Department of Applied Chemistry, Ritsumeikan University, Kusatsu, Shiga

525-8577, Japan^1

关键词: Catalytic performance;    Cr catalysts;    Cr species;    Impregnation methods;    Inter-atomic distances;    Oxidation state;    Supporting material;    Surface oxygen;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/712/1/012073/pdf
DOI  :  10.1088/1742-6596/712/1/012073

来源: IOP

【 摘 要 】

The catalytic performance is largely affected by the oxidation state of supported Cr species, and its control changes the activity of Cr catalysts and the selectivity of products. In this study, the calcination process of the supported Cr catalysts on γ-Al2O3and SiO2was investigated by in-situ XAFS spectroscopy. The hydrate species was first supported by the impregnation method and was converted to CrO3via Cr2O3during the calcination process on both supporting materials. It was found that the temperature to complete the oxidation from Cr2O3to CrO3on SiO2was higher than that on γ-Al2O3. The similarity of the interatomic distance between the surface oxygen atoms of the intermediate Cr2O3species to that of SiO2contributes to the stabilization of Cr2O3on SiO2during the calcination process.