Comparative Study of Vanadium Supported on MCM-36 and MCM-22 and Their Catalytic Perfomance in C3-ODH

In this work, we report successful preparation of hierarchical V-MCM-36 zeolitic catalyst. Vanadium was introduced onto the zeolite support by impregnation, using vanadyl acetylacetonate as a metal precursor and its subsequent solid state ion exchange during calcination. A conventional three-dimensional V-MCM-22 zeolite was prepared by the same way. Both zeolitic catalysts were characterized by nitrogen adsorption isotherms, X-ray fluorescence, temperature-programmed reduction by hydrogen (H2 -TPR), EPR, FT-IR, diffuse reflectance UV–vis, and Raman spectroscopy. The effect of pillaring and the presence of a combination of micro- and mesopores on catalytic behavior were tested in the oxidative dehydrogenation of propane (C3–ODH) at 540 °C. Obtained results clearly showed that activity of vanadium in zeolitic support is very similar to activity of vanadium in mesoporous silica catalysts. It was also found that hierarchical catalyst is slightly more selective toward propene and exhibits more stable activity than three-dimensional V-MCM-22 catalyst due to a lower rate of carbon deposit formation.