Abstract: Various Co-HZSM-5 and Co-NaZSM-5 zeolites, prepared by means of liquid-phase ion-exchange method, were characterized by means of NH₃-TPD, IR, UV-Vis and H₂-TPR for studying the relationship between the acid-base or redox properties and the catalytic ammoxidation performance of ethane. For both types of Na- and H-ZSM-5, the introduction of Co²⁺ cations results in the formation of two new types of Lewis acid sites. The presence of co-cations (i.e. H⁺ and Na⁺) has a great effect on the redox properties of Co²⁺ ions, thus influencing the catalytic activity and selectivity for the reaction of ethane ammoxidation.

Key words: Co-ZSM-5, characterization, ethane, ammoxidation