ABSTRACT
Zeolites are porous aluminosilicate structures and are derived from silica and alumina ceramic oxides. They are of great importance in catalytic cracking of hydrocarbons as will be described later. In zeolites with a framework consisting of large holes or cages, gas molecules can move in and out of them with ease and the structures also have large ions and water molecules with a considerable degree of movement. Zeolites are capable of accommodating gas molecules (or promoter ions) in the size range 0.3-1 nm. Recently larger sizes have been reported. The large surface areas associated with zeolites and active sites that can be distributed throughout the sample make zeolites excellent catalysts. Because they are not toxic materials, they are increasingly able to meet the rigid demands of environmentally safe standards of modern industrial processes.
