Cordierite-Like Catalyst Supports Based on Clay Materials

Abstract

The possibility of lowering the temperatures of crystallization of spinel-like cordierite, mullite, MgAl₂O₄, and corundum was studied. The following naturally occurring clay materials were used for the synthesis of supports: bentonite, clay, and kieselguhr. The effect of the preparation procedure on the structure and texture characteristics of the resulting supports was found. The composition of the resulting samples varied over the following ranges: clay material, from 45 to 60%; Al₂O₃, from 30 to 42%; and MgO, from 10 to 20%. Conditions responsible for spinel formation in cordierite and mullite phases over the temperature range 1050–1150°C were found. At the same parent composition, the thermal stability of supports prepared by coprecipitation was higher than that of composites prepared by mechanical mixing, as found using X-ray diffraction analysis and measuring specific surface areas and mechanical strength. The supports synthesized are promising for the preparation of supported catalysts for high-temperature processes.