The cracking of n-hexane over H-ZSM-5 has been studied at pressures from 0.03 to 137 bar, between 558 and 633 K, for application to endothermic reforming. The rates showed the effects of saturated adsorption for n-hexane in the zeolite, with the reaction being first-order at low pressures and zeroth-order at high pressures. The activation energy also changed with increasing pressure by an amount equal to the heat of adsorption of n-hexane in ZSM-5, going from 90 to 170 kJ/mol. The selectivity for C-7+ products varied only with temperature and conversion.