STUDY OF THE AROMATIZATION OF C_4 HYDROCARBON MIXTURE OVER MODIFIED HZSM-5 ZEOLITE
Xu Peiruo Bankala N.D. Wu Zhinan Wu Zhaojiong Department of Chemical Engineering, East China University of Chemical Technology, Shanghai
HZSM-5 zeolites modified by Zn, Ga, Cr and La were studied by TPD and IR to characterize their surface acid properties, and the results were correlated with that of the aromatization of a C_4 hydrocarbon mixture (without i-butene) .The experiment results showed that Zn(3%) HZSM-5 and Zn(2%) Ga (1%) HZSM-5 zeolite catalysts possess higher activity of aromatization than others. With the decrease of total acidity, the activity of aromatization decrease.With the decrease of strong Bronsted acid sites, cracking reactions decrease. The high aromatization activity of one-component (Zn) and two-component (Zn-Ga and Zn-Cr) modified HZSM-5 catalysts may be corrolated to the 1615cm~(-1) peak in the absorption spectra of adsorbed pyridine and the increase of strong Lewis acid sites.