화학공학소재연구정보센터
Petroleum Chemistry, Vol.34, No.1, 7-15, 1994
EFFECT OF PRELIMINARY HEAT-TREATMENT ON THE CATALYTIC ACTIVITY AND SELECTIVITY OF H-PENTASILS, GA-PENTASILS AND ZN-PENTASILS IN CONVERSIONS OF C4 HYDROCARBONS
A study has been made of the catalytic properties of H-, Ga-and Zn-pentasils calcined in air at 600-1000-degrees-C in conversions of isobutane and isobutylene. It has been shown that, by varying the treatment temperature t(tr), it is possible to control the catalytic activity of pentasils and the selectivity of formation of aromatization, dehydrogenation and cracking products. The conditions of dehydrogenation of isobutane on Zn-pentasil with a selectivity of >70% have been established. IR spectroscopy of adsorbed pyridine has been used to study the acidic properties of pentasils, and the high thermal stability of aprotic acid centres formed as a result of modification of the zeolite matrix with zinc or gallium has been found. On the basis of catalytic and spectral data, the role of Bronsted and Lewis acid centres in the acceleration of individual stages of conversion of low-molecular weight paraffins and olefins on decationized and modified pentasils is discussed.