Dehydrogenation of propane over Pt-Sn/θ-Al2O3 catalyst prepared by co-impregnation: the influence of the solvent

The effect of the solvent used for impregnation of alumina with acidic solutions of H2PtCl6 and SnCl2 on the properties of Pt-Sn/θ-Al2O3 catalysts was studied. The catalysts were prepared by coimpregnation of the support with the metalic precursors using water, acetone and ethanol as the solvent. The performance tests for propane dehydrogenation were carried out in a fixed quartz reactor. It was found that the catalysts prepared in ethanol gives the highest propylene yield which can be attributed to the higher active metal dispersions. This can be explained in term of the polarity and boiling point of the solvent employed, as well as, the stability of complex formed in different solvents. The activity of catalysts decreases in the order ethanol> water≥ acetone. However, regarding catalyst satiability, the order was water>ethanol> acetone. A kinetic model was used to quantify and compare the activity of stability of the catalysts. With a considerably lower precious metal platinum content, the catalyst prepared in ethanol showed similar performance to that of the reference commercial catalyst.