Effect Of The Solvent Used During Preparation On The Properties Of Pt/Al 2 O 3 And Pt−Sn/Al 2 O 3 Catalysts

Abstract

The influence of the solvent (water, acetone, and ethanol) used during alumina impregnation on the properties of Pt/Al2O3 and Pt−Sn/Al2O3 catalysts was studied. Catalysts were characterized by H2 chemisorption, TEM, temperature-programmed reduction, ammonia temperature-programmed desorption, UV−vis spectroscopy and cyclohexane dehydrogenation, n-pentane isomerization, and n-octane reforming reactions. It was found that the catalysts prepared in ethanol has the highest metallic dispersion. The results are explained considering the Pt−Sn complex stability in the different solvents used during the preparation. Pt/Al2O3 (acetone) is the most active catalyst for isomerization while the activity of Pt−Sn/Al2O3 catalysts decreases in the order ethanol > acetone > water. The selectivity to aromatic hydrocarbons is related to isomerization activity, but there also exits a competition between hydrocracking and dehydrocyclization.