Micro/mesoporous aluminosilicate composites from zeolite MCM-22 precursor

Abstract Micro/mesoporous aluminosilicate composites were prepared applying a two-step hydrothermal synthesis procedure. In the first step a zeolitic component, i.e., the precursor of zeolite MCM-22 was synthesized and its swollen and partially delaminated derivatives were prepared. In the second step mesoporous MCM-41 silicate was synthesized in a slurry of the above MCM-22 type precursor from additional silicate source and using hexadecyltrimethylammonium bromide (CTMABr) template. The structure, morphology and the acidic properties of the obtained composite materials were characterized by X-ray diffraction, infrared spectroscopy, N 2 adsorption isotherms, and electron microscopy (SEM and TEM). The results suggest that the composite materials were built from nanosize, randomly orientated stacks of thin layers of MCM-22 type zeolite and of mesoporous silicate MCM-41 material. The catalytic activity of the composite material was compared to that of the zeolite MCM-22 in the hydroconversion of heptane.