Nature of the active sites in H-ZSM-11 zeolite modified with Zn(2+) and Ga(3+)

OSCAR A. ANUNZIATA AND LILIANA B. PIERELLA.

CATALYSIS LETTERS

SPRINGER

Año: 1993 vol. 19 p. 143 - 151

1011-372X

H-ZSM-11 zeolite modified with zinc and gallium by ion exchange was investigated using XRD, IR and TPD of ammonia. The modification of the material by zinc produced a lowering of the strong Brønsted acidic sites generating new and strong Lewis sites. Unlike zinc-zeolites, the gallium is localized preferentially on the outer surface of microcrystallites blocking a few Brønsted centers.