Effect of preparation method on platinum-ceria catalysts for hydrogen iodide decomposition in sulfur-iodine cycle

摘要

In this work, three catalysts, Ce_(0.99)Pt_(0.01)O_2 called the Pt-doping sample, Pt/CeO_2 called the Pt-loading sample and pure CeO_2, have been tested to evaluate their effect on hydrogen iodide (HI) decomposition in sulfur-iodine (SI or IS) cycle at various temperatures. BET, XRD, TPR and TEM were performed for catalysts characterization. Platinum was introduced into ceria to form the Pt-doping sample by sol-gel. It was found that, through sol-gel method, the Pt ions could be inserted into the ceria lattice. This brought about a different synergistic effect between the Pt and Ce components in the Pt-doping sample by comparison with the Pt-loading sample prepared by traditional impregnation, such as increase of the oxygen mobility in ceria support and improvement of the thermal stability of catalyst. Indeed, the pure CeO_2 also strongly enhances the decomposition of HI to H_2 by comparison with blank yield, and the Pt-doping and Pt-loading samples show better catalytic activity, especially the Pt-doping sample. These provide this material with a potential to be used in SI cycle for hydrogen iodide decomposition.