This invention provides catalytic proton and electron mediating membranes useful in catalytic reactors. The membranes have an oxidation and a reduction surface and comprise a single-phase mixed metal oxide material of the formula: ...http://www.google.co.uk/patents/US5821185?utm_source=gb-gplus-sharePatent US5821185 - Solid state proton and electron mediating membrane and use in catalytic membrane reactors 
