Reactions of n-hexane on Pt-Sn/Al2O3 and removal of retained hydrocarbons by hydrogenation

n-hexane was reacted on two Pt-Sn/Al2O3 catalysts, one prepared by coimpreg nation (T) the other by using a bimetallic PtSn complex precursor (N). Both catalysts produced isomers, methylcyclopentane fragments and benzene, the aromatic selectivity being higher on catalyst N. The hydrocarbon entities r emaining after reaction were removed by hydrogen treatment. They contained methane, C-2-C-5 fragments (not observed on Pt, thus unique for PtSn) and b enzene. The possible state and composition of chemisorbed carbonaceous enti ties during reactions are discussed. More hydrocarbons, including slightly more methane could be hydrogenated off from catalyst N of lower dispersion. The higher overall activity of catalyst N in the presence of more than one C per surface Pt points to its higher coke tolerance.