| Abstract: | Four catalysts, H2PtCl6-5SnCl2/γ-Al2O3 (cat-1), { H2PtCl6-5SnCl2 + xLaCl3 } / γ-Al2O3 (cat-2), (Me4N)Pt(SnCl3)5]/ γ-Al2O3
(cat-3), and {(Me4N)Pt(SnCl3)5] + xLaCl3} / γ-Al2O3 (cat-4) were prepared and their catalytic activities and stabilities
in dehydrogenation of propane were investigated. It has been shown that the stabilities of the Pt-Sn bimetallic catalysts
were improved by introducing lanthanum into the catalysts either by the conventional impregnation method with Pt- and Sn-containing
salts or by using precursors derived from Pt-Sn bimetallic clusters. Results from XPS analysis indicated that addition of
lanthanum could inhibit the reduction of tin in the catalysts, especially in cat-2. The distribution of pore capacity in a
used cat-2 was mainly in the large and medium size range, but in a used cat-1 the distribution was mainly in the small to
medium size range. Thermal gravimetric analysis (TGA) showed that weight loss in the used cat-1 was much more than that in
the used cat-2. The results suggested that introducing lanthanum into the Pt-Sn bimetallic catalysts could effectively prevent
them from coking.
This revised version was published online in July 2006 with corrections to the Cover Date. |
