Aromatization of Heptene-2 on Pt/Al2O3 Catalysts

Heptene-2 aromatization on Pt/Al₂O₃ in a pulse microcatalytic reactor has been studied under H₂ and N₂ atmosphere at temperatures between 330 to 500°C and at a total pressure of 4.0 kg/cm². Results showed that the production of only cracked products (mainly methane) from deep fragmentation of heptene-2 in H₂ sharply contrasts with the reaction in N₂ in which the catalyst showed aromatic selectivity with the production of methane, benzene and toluene. In H₂-N₂ mixtures, 75% H₂ was required to reduce the aromatization activity of the catalyst to zero. A test of the kinetic data using Sica's method 15] of pulse kinetic analysis suggests a first order in heptene-2 with an activation energy of 102.61 kJ/mol in N₂ and 124.71 kJ/mol in H₂. The difference in activation energies has been attributed to a difference in reaction mechanisms in both gases.