The Investigation on the Crystallinity of USY Zeolite during Hydrothermal Dealumination

Hydrothermal dealumination is an important way for improving hydrothermal stability and catalytic activity of Y-zeolite. The changes in relative crystallinity of zeolite E prepared by hydrothermal-chemical dealumination and zeolite A prepared by conventional hydrothermal dealumination were characterized by IR, XRD, TEM, etc.. It was illustrated that the crystallinity of product E was greater than that of its precursor, HY. As compared with zeolite A, the zeolite E possessed higher crystallinity (≊100%) and more developed secondary pore system which would benefit bottoms conversion.