Ordered functionalized silica materials with high proton conductivity

A simple and fast method for the preparation of the Si-MCM-41 functionalized with sulfonic acid groups (SO3H) was developed. It is based on a co-condensation synthesis and microwave treatment, which ensures an effective removal of the template (cetyltrimethylammonium bromide) and the simultaneous oxidation of thiols to SO3H groups. The obtained hybrid materials exhibit a very high proton conductivity of up to 0.2 S/cm at 100% relative humidity, which increases continuously with the temperature. The coverage of the MCM-41 pore walls with the propyl chains bearing the SO3H groups is so high that more than one SO3H group is present per nm(2) of the inner surface.