Characteristics of the metallic phase of Pt/Al2O3 and Na-doped Pt/Al2O3 catalysts for light paraffins dehydrogenation

The influence of the Na addition to Pt/Al2O3 catalysts is analyzed in this paper, not only on the characteristics and properties of both the acid and metallic function, but on the activity, selectivity and deactivation in the n-butane dehydrogenation reaction.The addition of increasing amounts of Na to Pt/Al2O3 catalyst modifies both the nature of the acid function (by poisoning the stronger acid sites) and the metallic phase (by a geometric modification the metallic phase). These modifications would be the responsible for the sharp diminution of deactivation of the catalysts due to the carbon deposition. Na addition to Pt/Al2O3 catalysts inhibits the formation of coke deposited on the metallic sites and the support.