CHARACTERIZATION OF MODIFIED ZSM-5 CATALYSTS FOR PROPANE AROMATIZATION PREPARED BY A SOLID-STATE REACTION

This paper describes a simple preparation method using a solid state reaction for Zn-, Mo-, and Cr-ZSM-5 catalysts for propane aromatization. NH,3-temperature-programmed desorption, infrared, temperature-programmed reduction and electron spin resonance techniques were used to characterize the interaction of H-ZSM-5 with ZnO, MoCl5 and CrO3 respectively, which leads to introduction of cations into the channels of the zeolite. A solid-exchange mechanism is suggested here. Zn-ZSM-5 is the most active catalyst for propane conversion and gives a better benzene, toluene and xylenes selectivity, Over Mo-ZSM-5, propane mainly undergoes cracking to methane and ethane, and the loading ZSM-5 with Cr5+ enhances the propane dehydrogenation to propene