Abstract: Vanadium has been introduced into high-silica zeolites by heating the physical mixture of V_2O_5 and H-Mordenite or H-ZSM-5 in an airflow containing water vapor. XRD, LRS, BIE and FTIR results suggest that ion exchange occurs between protons of zeolite and the (VO)~(3+) formed during preparation. ESR results show these are two different coordination structures for the vanadyl species entered into HM or H-ZSM-5, i.e. The compressed hexacoordinated octahedral and the pentacoordinated with pyramidic symmetry.

Key words: Solid-state Ion-exchange, V₂O₅, Zeolite