STUDY OF CATALYTIC PROPERTIES AND ACID CENTERS OF DECATIONATED LANTHANUM ZEOLITES LAHY

Infrared spectroscopy has been used to investigate the acid centers of LaHY zeolites. For samples with a degree of exchange alpha less-than- or-equal-to 0.48, the activity in the conversion of n-octane and isooc tane is independent of the La3+ content; with further increases in the degree of exchange, the activity decreases sharply. It has been estab lished that OH groups in the LaHY with an absorption band at 3630 cm-1 are responsible for the cracking of paraffinic hydrocarbons; the acti vity of LaHY in cracking paraffins is determined by the distribution o f La3+ in the lattice. The nature of the OH group bound to La3+ is exa mined critically.