Comparative study of the vanadium species in VAPO-5 and VAPSO-5 molecular sieves

The nature and location of vanadium species between VAPO-5 and VAPSO-5 molecular sieves are comparatively studied using XRD, TG-DTA, NMR and UV resonance Raman spectroscopy. It is observed that the framework vanadium ions are formed in VAPSO-5 but are difficult to form in VAPO-5 and that the silicon ions in VAPO-5 play an important role in the formation of framework vanadium species.