The reactions taking place involving Zeolites depend on(A) Pores & cavities of Zeolites;  (B) size of reactant and product molecules(C) shape of reactant and product molecules

Zeolites are micro porous aluminosilicates with 3D network of silicates having Al-O-Si frame work.They can accomodate only certain reactants and produce only certain products which can fit intotheir cavities.Thus pore size of Zeolites, size & shape of reactant & product moleculesdecide  the reactions  involving Zeolites