Preparation, characterization and catalytic behavior in methanol decomposition of nanosized iron oxide particles within large pore ordered mesoporous silicas

Nanosized iron oxide particles within various ordered mesoporous silicas (SBA-15, SBA-16, Fm3m, Ia3d) have been prepared from the corresponding nitrate and acetylacetonate precursors. N2 physisorption, X-ray diffraction and Moessbauer spectroscopy are used for their characterization. The reductive properties of the modified materials were investigated by temperature-programmed reduction with hydrogen. Methanol decomposition to H2, CO and methane was used as a test reaction. Some differences in the iron state, its phase transformations in reductive medium and also some variations in its catalytic behavior were observed and discussed in view of the iron oxide particle size dispersion and its dependency on the pore geometries of the silica supports.