SURFACE PROPERTIES AND CRACKING ACTIVITY OF DELAMINATED CLAY CATALYSTS.

Delaminated clays are solid supports and catalysts characterized by a house-of-card like structure containing, in addition to micropores of the type found in zeolites and pillared clays, mesopores and macropores characteristic of mixed oxides, aluminas and silicas. In these materials, 001 X-ray reflections are very diffuse due to a lack of long range FF stacking of the clay silicate layers. Short range FF layer ordering is believed to be responsible for the zeolite-like selectivity in cracking gas oil. This paper reviews and compares the properties of delaminated clays with those of pillared clays and aluminosilicate catalysts.