Abstract: The contaminations of Y zeolite by vanadium from different sources were conducted using ammonium metavanadate, vanadyl-naphthenate and vanadium pentoxide, respectively. The contaminented Y zeolites were than hydrothermally treated and investigated to see the destruction extent of treated Y zeolites. Results show that vanadium from different source has a different impact on Y zeolite structure. At the same vanadium content and hydrothermal treatment, the destroyed extent of Y zeolites is: vanadyl-naphthenate > ammonium metavanadate > vanadium pentoxide. This illustrates that for vanadium contamination experiment, the V source and contaminating way must be exactly the same. The results also indicate that the hydrothermal treatment is the most important factor affecting Y zeolite crystlinity. After hydrothermal treatment at 800 ℃, the mullite crystal phase was observed, without the formation of AlVO4, and REVO4 is generated in the case of REY. The V2O5 destroys the Y zeolite structure in a non-stoichiometric manner.

Key words: catalyst, contamination, deactivation, Y zeolite, vanadium, rare earth