Facile One-step Preparation of Mesoporous Siliceous phophsomolybdic acid for Proton Exchange Membrane

Background: Proton exchange membrane is art of PEM fuel cells, developing active materials with robust structure and high proton conductivity has attained huge attention in recent decade amongst researchers. Aims/objectives: Here we have developed a novel approach to prepare a siliceous mesoporous heteropoly acid with high stability in polar media and high proton conductivity to be utilized as proton exchange membrane. Methods: A highly stable mesoporous siliceous phosphomolybdic acid has been synthesized via a simple self-assembly between phosphomolybdic acid (PMA), the polymeric surfactant, and the silica precursor stabilized by KCl molecules as a proton conducting material for proton exchange membrane application. Results: As prepared siliceous mesoporous phosphomolybdic acids (mPMA-Si) show a high surface area with a highly crystalline structure, however the crystallinity reduced by increasing the silica content. Further analysis proved the Keggin structure remain intact in final materials. mPMA-8 Si shows the highest performance among all the materials studied with proton conductivity of 0.263 S.cm-1 at 70 oC. Conclusion: As prepared mPMA-xSi has shown a very high proton conductivity in a range of temperatures which make them a promising material for proton exchange membrane.