Synthesis and Characterization of Titanium-Zirconium Modified Ultrastable Y Zeolite for Hydrocracking



    In this study commercial ultrastable Y zeolite was modified by different synthesis methods as precipitation, impregnation, and thermal hydrolysis, with different titanium and zirconium precursors. The intention was to investigate the effect of these metals in the framework on the zeolite acidity properties and how this influences the performance of the final catalyst on oil processes such as hydrocracking. For precipitation modification, different samples were synthesized varying the time precipitating ranging from one injection up to 9 hours. Samples in impregnation modification were synthesized along with thermal hydrolysis to compare different modification synthesis methods. Zeolite has a strong dealumination effect below pH 2 but low pH is needed to maintain titanium precursor in solution. Thermal hydrolysis shows an improvement in activity compared to precipitation and impregnation better selectivity compared to thermal hydrolysis. Metals preserve aluminum content when exposed to acidic post-treatment and shows improvements in yield of isomers compared to blanks. NH3-TPD showed decrease of weak and strong acid sites with increase of medium acid sites when exposed to acid post-treatment. BAS controls the yield of isomers.
    Date made available2021
    PublisherKAUST Research Repository

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