NaY FRAMEWORK DESILICATION INDUCED MESOPORE FORMATION IN USY ZEOLITE AND ITS APPLICATION AS THE ACTIVE COMPONENT OF HEAVY OIL CATALYTIC CRACKING CATALYST

摘要

The increasing demand on lighter products requires refineries to use more efficient and selective catalysts to process heavier crude oils. Recent efforts to improve heterogeneous catalysts have focused on hierarchical zeolites to improve accessibility and enhance selectivity.1-2 Stimulated by the enormous interest in the applications of dealuminated Y zeolite in fluid catalytic cracking and hydrocracking, various post synthetic techniques have indeed been developed for increasing the Si/Al ratio and mesoporosity of Y zeolite.2-12 Here we would like to report the preparation of two dealuminated Y zeolites by steaming with and without the interference of predesilication and the investigation of how desilication creates defects in NaY framework and its influence to the mesoporosity properties of the final product USY (ultrastable Y).