Acid-functionalised periodic mesoporous benzenosilica proton conductors
Abstract An investigation of proton conducting periodic mesoporous benzenosilica hybrids functionalised with sulfonic or phosphonic acids obtained by a co-condensation route is presented. Protonic conductivity data obtained under different temperatures and relative humidity conditions are reported in order to assess the combined effects of composition and concentration of the functional acid group, and microstructural features such as pore size, specific surface area and meso- and molecular-scale order. It is found that the conductivity increases significantly with increasing acid load, specific surface area and relative humidity. A proton conductivity of 0.3 Sm − 1 at 100 °C and 100% relative humidity is reported for a sulfonic acid functionalised PMO which is three orders of magnitude higher than the value reported for a similar material obtained by grafting.