Effects of the composition on the active carbon supported Pd-Pt bimetallic catalysts for HI decomposition in the iodine-sulfur cycle

摘要

A series of binary Pd-Pt catalysts supported on active carbon were prepared by the co-impregnation and reduction method. For comparison, active carbon supported mono-metallic Pt and Pd catalysts were also prepared by the impregnation-reduction method. Their structure, morphology and surface area were investigated by means of X-ray diffraction (XRD), Transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) surface area, respectively. Their catalytic activities were evaluated for the decom-position of hydrogen iodide (HI). Furthermore, their thermal stabilities were also investi-gated. The results of activity tests showed that the composition of Pd-Pt binary catalysts played the important role in dictating the catalyst activity. Among the Pt, Pd and binary Pd -Pt catalysts, the 2.5%Pd-2.5%Pt/C showed the best catalytic performance for the decomposition of HI. The results of thermal stability tests showed that the binary Pd-Pt catalyst had the higher stability than the monometallic Pt and Pd catalysts.