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, N2 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 °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.