Heptene-2 aromatization on Pt/Al2O3 in a pulse microcatalytic reactor has been studied under H-2 and N-2 atmosphere at temperatures between 330 to 500 degreesC and at a total pressure of 4.0 kg/cm(2). Results showed that the production of only cracked products (mainly methane) from deep fragmentation of heptene-2 in H-2 sharply contrasts with the reaction in N-2 in which the catalyst showed aromatic selectivity with the production of methane, benzene and toluene. In H-2-N-2 mixtures, 75% H-2 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 N-2 and 124.71 kJ/mol in H-2. The difference in activation energies has been attributed to a difference in reaction mechanisms in both gases.