Dehydrogenation of propane on chromia/alumina catalysts promoted by tin

Dehydrogenation catalysts based on chromia supported on gamma-alumina, containing about 3 wt.% of chromium and increasing amounts of tin (up to 3 wt.%), were prepared and characterized by means of several techniques, such as N-2 adsorption-desorption at 77 K, X-ray power diffraction (XRPD), laser Raman spectroscopy, temperature programmed reduction (TPR) and chemical analyses. The catalytic behavior of the samples was investigated in the propane dehydrogenation reaction at 883 K. The coking formation (in 150 min of time of stream) was analyzed by temperature programmed oxidation (TPO). The addition of increasing amounts of the tin determined a general decrease in the coking formation. TPR profiles of the Sn-containing samples showed the presence of one reduction peaks, which decreased in intensity at high tin loading. (C) 2007 Elsevier B.V. All rights reserved.