AROMATIZATION OF PROPANE OVER ZN HZSM-5 CATALYSTS PREPARED BY CHEMICAL-VAPOR-DEPOSITION/

Zinc was introduced into HZSM-5 by chemical Vapor deposition (CVD) to investigate the catalytic properties of Zn/HZSM-5 for propane conversi on. Irrespective of catalytic precursor or ion exchange method, proton s were found to be replaced by Zn ions. However, Zn species in the zeo lite were different depending on the precursors used. Although the add ition of Zn decreased the intensity of the Bronsted acidity, it did no t caused the apparent formation of Lewis acid sites unlike Ga/HZSM-5 c atalysts. On Zn/HZSM-5, both Zn and protons intervene in propane activ ation step.