FCC Catalyst:Zeolite ZSM*5

ZSM*5 is mainly used for hydrocarbon interconversion, meta-xylene to para-xylene, for example. ZSM*5 is a zeolite with a high silica to alumina ratio.

The substitution of an aluminum ion (charge 3+) for a silicon ion (charge 4+) requires the additional presence of a proton. This additional proton gives the zeolite a high level of acidity, which causes its activity.

ZSM*5 is a highly porous material and throughout its structure it has an intersecting two-dimensional pore structure.

ZSM*5 has two types of pores, both formed by **-membered oxygen rings. The first of these pores is straight and elliptical in cross section, the second pores intersect the straight pores at right angles, in a zig-zag pattern and are circular in cross section.