Iron oxide nanoparticles inside the MCM-41 channels: Study of the structural stability of the support

When the support was synthesized without pH adjustment the preparation steps of the supported system, the water destroys the regular structure of hexagonal channels of the mesoporous solid. The structure is preserved when the support is synthesized with pH adjustment during the synthesis process due to its higher pore-wall thickness. In addition, this system has a higher percentage of the iron oxide nanocrystals located inside the channels of the support.