Proton conducting ceramic polymer composite membrane for use at temperatures up to 300°C

A proton conductive polymer/ceramic particle composite or composite membrane, consisting of a polymer and oxide nanoparticles with intercalated water and high surface hydroxyl concentration, is new. A novel proton conductive polymer/ceramic particle composite or composite membrane consists of a temperature resistant polymer and oxide nanoparticles (much greater than 20 m 2>/g surface and much less than 100 nm mean diameter) with intercalated water and a high concentration of acidic/basic surface OH. Independent claims are also included for the following: (i) a hydroxyl ion conductive polymer/ceramic particle composite as described above, in which the polymer can contain anion exchange groups of NR 4(R = H, alkyl, aryl), pyridinium, imidazolium, pyrazolium, sulfonium; and (ii) production of the above hydroxyl ion or proton conductive polymer/ceramic particle composite by dispersing the polymer and the nanoparticles in a solvent and then evaporating off the solvent.