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On the Active Surface State of Nickel-Ceria Solid Oxide Fuel Cell Anodes During Methane Electrooxidation
- Source :
- Advanced Energy Materials. 3:762-769
- Publication Year :
- 2013
- Publisher :
- Wiley, 2013.
-
Abstract
- Solid oxide fuel cells (SOFCs) have grown in recognition as a viable technology able to convert chemical energy directly into electricity, with higher effi ciencies than conventional thermal engines. Direct feeding of the SOFCs anode with hydrocarbons from fossil or renewable sources, appears more attractive compared to the use of hydrogen as a fuel. The addition of mixed oxide-ion/electron conductors, like gadolinium-doped ceria (GDC), to commonly used nickel-based anodes is a well‐known strategy that signifi cantly enhances the performance of the SOFCs. Here we provide in situ experimental evidence of the active surface oxidation state and composition of Ni/GDC anodes during methane electroxidation using realistic solid oxide electrode assemblies. Ambient pressure X-ray photoelectron and near edge X-ray absorption fi ne structure spectroscopies (APPES and NEXAFS respectively) combined with on line electrical and gas phase measurements, were used to directly associate the surface state and the electrocatalytic performance of Ni/GDC anodes working at intermediate temperatures (700°C). A reduced anode surface (Ce 3+ and Ni), with an optimum Ni to Ce surface composition, were found to be the most favorable confi guration for maximum cell currents. Experimental results are rationalized on the basis of fiprinciples calculations, proposing a detailed mechanism of the cell function.
- Subjects :
- Materials science
Renewable Energy, Sustainability and the Environment
Inorganic chemistry
Oxide
chemistry.chemical_element
02 engineering and technology
Active surface
010402 general chemistry
021001 nanoscience & nanotechnology
7. Clean energy
01 natural sciences
Methane
0104 chemical sciences
Anode
Nickel
chemistry.chemical_compound
chemistry
Hydrogen fuel
Electrode
General Materials Science
Solid oxide fuel cell
0210 nano-technology
Subjects
Details
- ISSN :
- 16146832
- Volume :
- 3
- Database :
- OpenAIRE
- Journal :
- Advanced Energy Materials
- Accession number :
- edsair.doi...........849a25fd41e40f4effe07b9bbc12c977