| Abstract
| - The aim of this work is to study the effect of the platinum content (0−1.8 wt % Pt) on the microstructure ofan alumina-pillared clay. For this purpose, the nitrogen physisorption data at −196 °C, the micropore sizedistributions of the supported platinum catalysts, and the hydrogen chemisorption results at 30 °C have beenanalyzed and compared. The preparation of the catalysts has modified the textural properties of the Al-pillared clay support, giving rise to a loss of surface area and micropore volume. After reduction at 420 °C,the presence of dispersed metallic platinum with mean crystallite size in the 22−55 Å range has been foundby hydrogen adsorption. Comparison of all results reveals that the platinum species block the microporeentrances by steric hindrance to nitrogen access as the platinum content increases.
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