Characterization of galloaluminosilicate MCM-41 molecular sieve

A series of mesoporous galloaluminosilicate MCM-41 molecular sieves with va rious compositions have been synthesized. Hexadecyltrimethylammonium bromid e was used as an organic surfactant in the synthesis. These materials were characterized with nitrogen sorption, powder X-ray diffraction (XRD), diffe rential thermal analysis (DTA), thermogramitric analysis (TGA), scanning el ectron microscope (SEM), transmission electron microscope (TEM) and solid s late NMR. The solid products had the MCM-41 structure and contained only at omically dispersed gallium consistent with the framework gallium in MCM-41. Incorporation of either Ga or Al into the framework of MCM-41 affects the long-range order of the mesopores without damaging the essentially mesoporo us nature of the materials. Gallium was easier to incorporate into the fram ework than aluminum. All of the materials had a uniform pore size distribut ion with pore size around 30 Angstrom. The morphologies of [Ga, Al]-MCM-41 were spherical particle packages. A small amount of aluminum had been expel led from the framework of MCM-41 upon calcination at 550 degrees C.