Abstract:

The structural properties of four kinds of USY zeolites were investigated by catalyst characterization techniques. The activity was evaluated with FCC MAT method. The results indicate that increasing total Al2O3 amount or Si(1Al)ratio means larger lattice constant, less Al2O3 amount and extra-framework Al; higher ratio of Si(1Al) is needed for better thermal stability; larger crystal constant, larger micro-pore surface area and pore volume with unobstructed pore channel are required for better acidity and higher activity. The higher ratio of extra-framework Al and Si is favor of formation of L-acid.

Key words: USY zeolites, Al2O3 amount, lattice constant, extra-framework Al, Si(1Al) structure