Characterization of Supported Chromium Sesquioxide Catalysts and Oxidative Dehydrogenation of Isobutane

摘要

A set of (―Al_2O_3 catalysts with different chromium loading for oxidative dehydrogenation of isobutane is prepared by impregnation method and characterized by X- ray photoelectric spectroscopy (XPS). XPS results reveal that moderate activation temperature (400 (C) is advantageous to the transformation of Cr(Ⅲ) into Cr(Ⅵ) and the fraction of Cr(Ⅵ) species increases with the decrease of Cr2O3 loading. The performance of oxidative dehydrogenation (ODH) of isobutane presents that the lowest chromium loading of the catalyst gives the highest specific activity, suggesting that the Cr(Ⅵ) species is the active phase in ODH of isobutane.