Effect of carbon addition on the Pt-Sn/(gamma) Al2O3 catalyst for long chain paraffin dehydrogenation to olefin

Carbon-covered alumina (CCA) was prepared by the pyrolysis of the sucrose dispersed on a gamma alumina surface. BET, mercury porosimetry, SEM, XRD, H2-chemisorption, CO-chemisorption, NH3-TPD and TG-DTA were used for the carriers and the corresponding catalyst characterization. The results showed that the carbon of the CCA samples had negative influence on the catalytic initial activity of the Pt-Sn/CCA catalysts for the dehydrogenation of n-octadecane, but it was helpful to enhance the selectivity of the products and especially the stability of the catalysts markedly.