Direct synthesis of disordered micro-mesoporous molecular sieve

A direct method to controlled synthesis of micro-mesoporous ZSM-5/KIT-1 molecular sieves using dual templates is reported. The framework structure, porosity and morphology of the obtained materials were characterized by X-ray diffraction, infrared spectroscopy, UV-Raman spectroscopy, N-2 adsorption isotherm, and electron microscopy (SEM and TEM). it was found that the crystallization temperature is a key to control the framework structure as well as the morphology and hydrothermal stability. Two-phase structure is more favored at higher temperatures, while pure mesophase structure with ZSM-5 building units is formed at lower temperatures. The ZSM-5/KIT-1 crystallized at 130 degrees C possesses excellent micro-mesoporous structure and good hydrothermal stability. This type of material has a disordered three-dimensional micro-mesopore network structure with narrow pore size distribution and high surface area, which will provide new opportunities for catalytic reactions involving large molecules. (C) 2009 Elsevier Inc. All rights reserved.