Tin containing mesoporous silicas with various tin contents were prepared by reaction of tetrabutyl tin with the surface silanol groups of calcined MCM-41 followed by thermal treatment under oxygen. Various physicochemical methods (XRF, FTIR, XRD, HRTEM, N 2 adsorption, UV–vis spectroscopy, …) and the catalytic hydroxylation of phenol by H 2 O 2 were used to characterize the resulting materials. It is shown that the materials prepared by this way have a better hydrothermal stability and a higher catalytic activity than tin containing MCM-41 prepared by conventional methods (mechanical mixture of nano-sized SnO 2 and MCM-41, impregnation of MCM-41 by SnCl 4 or hydrothermal synthesis).