Behavior of pure and doped ceria in molten alkali carbonates
Niobium-doped cerium (IV) oxide was studied as an alternative cathode material for molten carbonate fuel cells. Studies of corrosion by molten (Li,K){sub 2}CO{sub 3} eutectic in air and controlled atmospheres were conducted, as well as microstructural studies (TEM, SEM) and DC electrical-conductivity measurements. The corrosion resistance and electrical conductivity of niobium-doped cerium oxide was strongly affected by material-preparation procedures. Silicate grain-boundary phases, attributed to contamination from grinding during powder preparation, served as a sink for the dopant and were readily attacked by the molten carbonate. As a result, materials prepared from mixed oxides showed poor corrosion resistance and low electrical conductivity. However, it is concluded that Nb-doped ceria can be a good alternative as a cathode material for molten carbonate fuel cells when it is prepared by techniques that avoid silicate intergranular phases.
- Research Organization:
- Case Western Reserve Univ., Cleveland, OH (United States)
- OSTI ID:
- 5400575
- Country of Publication:
- United States
- Language:
- English
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36 MATERIALS SCIENCE
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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
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ALKALI METAL COMPOUNDS
CARBON COMPOUNDS
CARBONATES
CATHODES
CERIUM COMPOUNDS
CERIUM OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
CORROSION
CORROSIVE EFFECTS
DIRECT ENERGY CONVERTERS
DOPED MATERIALS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTROCHEMICAL CELLS
ELECTRODES
ELEMENTS
FUEL CELLS
HIGH-TEMPERATURE FUEL CELLS
LITHIUM CARBONATES
LITHIUM COMPOUNDS
MATERIALS
METALLURGICAL EFFECTS
METALS
MOLTEN CARBONATE FUEL CELLS
NIOBIUM
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POTASSIUM CARBONATES
POTASSIUM COMPOUNDS
RARE EARTH COMPOUNDS
TRANSITION ELEMENTS