Convenient solvent-free synthesis and characteristics of acid–base bifunctionalized MCM-41 mesoporous silicas

A series of acid–base bifunctionalized mesoporous silicas have been successfully synthesized by means of a convenient solvent-free approach. Through grinding the precursors, aluminium and magnesium nitrates, with the as-prepared MCM-41, and then the generation of acid–base sites and removal of host template were simultaneously completed in the subsequent calcination procedure. The resultant modified mesoporous silicas MgO–Al2O3–MCM-41 were characterized with X-ray diffraction, high-resolution transmission electron microscopes, N2 adsorption, FT-IR spectra, 29Si and 27Al MAS NMR, NH3− and CO2− temperature programmed desorption. The results indicate that the products exhibit excellent acid–base properties with well mesoporous structure, and the guests were well dispersed in the channel of MCM-41, which make it exhibit high activity for the synthesis of EMC.