Ceramic Proton and Mixed Proton-Electron Conductors in Membranes for Energy Conversion Applications

Abstract

Ceramic high temperature proton conductors offer in principle great advantages over oxide ion conductors and “proton conducting” polymers as electrolytes in fuel cells. This is related to the absence of product water on the anode, and simplified overall water management. The state-of-the-art proton conducting perovskite oxide materials are too basic to be stable in operation with reformed fossil fuels, and new classes of more stable proton conducting oxides have been discovered—so far with more moderate proton conductivities, though. Also new mixed proton-electron conducting oxides are being uncovered, and it is shown how they can be utilized as membranes in fossil fuelled power plants with CO₂ sequestration.