Synthesis and characterisation of MFI-type zeolites supported on carbon materials

A wide variety of silicalite/carbon and ZSM-5/carbon composites have been prepared by conventional hydrothermal synthesis. The influence of the surface chemistry and porosity of the carbon supports on the growth of the zeolite has been studied. The presence of oxygen surface groups on the carbon supports has been found to be necessary to allow the anchorage of the. zeolite layer on the carbon. In the cases of carbons with few surface groups an oxidising pretreatment favours the interaction between the synthesis solution and the carbon surface. Different synthesis conditions have been tried to evaluate their influence on the final properties of the composites. The use of clear synthesis solutions and the ageing time before the hydrothermal synthesis are key steps for the successful synthesis. The burn-off of the zeolite/carbon fibres and the zeolite/carbon cloths composites yields pure zeolite hollow tubes. (C) 2001 Elsevier Science B.V. All rights reserved.