(621b) Synthesis Of Sulfonic Acid-Functionalized Monodispersed Mesoporous Silica Spheres And Their Catalytic Activity For Condensation Reactions

A new type of sulfonic acid-functionalized monodispersed mesoporous silica spheres (MMSS) were synthesized directly by co-condensation and subsequent oxidation. By changing the methanol ratio, sulfonic acid-functionalized MMSS with different particle diameters (390-830nm) and the same mesopore sizes were successfully synthesized. TEM observations revealed that the mesopores were aligned radially from the center towards the outside of the spheres, even in the sulfonic acid-functionalized MMSS. The catalytic activities of the sulfonic acid-functionalized MMSS were studied in condensation reactions between 2-methylfuran and acetone, and it was found that their catalytic activities are highly dependent on the particle diameters, and the catalytic activity of MMSS was much higher than that of other forms of mesoporous silica due to its radially-aligned mesopores. In addition, a novel type of sulfonic acid-core / hydrophobic-shell monodispersed mesoporous silica spheres have been successfully synthesized for the first time. The catalytic performance of the core/shell particles was enhanced by a factor of 1.6 due to the adsorption effect by the shell layer.