Fuel-Flexible Anodes for Solid Oxide Cells
INVENTION: Northwestern researchers have developed new solid oxide fuel cell anodes that operate efficiently with a range of hydrocarbon fuels as well as hydrogen.ADVANTAGES: Solid oxide fuel cell anodes that directly utilize hydrocarbon fuels, without reforming and provide stable operation without electrode coking. The new anodes enhance fuel cell flexibility and utility with significant economic potential.
SUMMARY:Hydrogen is the principal fuel employed in present day fuel cells but requires a priori hydrogen generation. Fuel cells employing hydrocarbon feed stocks could utilize present day distribution infrastructure, expand fuel cell use and potentially reduce investment for this promising energy source. Solid oxide fuel cells (SOFCs) can employ hydrocarbon feed stocks directly or with internal reforming. However, SOFCs optimized for hydrogen do not perform as efficiently under direct hydrocarbon feed due to anode coking and other limitations.
This invention addresses these difficulties by creating new SOFC anode compositions. These anodes incorporate non-coking electronic and ionic conducting ceramics with a catalyst that effectively converts a variety of hydrocarbon fuels to electricity. The anodes are not affected by repeated oxidation-reduction cycles. A system of LaSrCrMnO (LSCM) and CeGdO (GDC) ceramics in conjunction with a Ni catalyst are synthesized in a unique process to afford anodes providing excellent mechanical and electrical properties, high temperature stability, and efficient hydrocarbon oxidation with minimal carbon formation. Cells employing the LSCM-GDC-Ni anodes, LaSrCoFeO (LSCF)/GDC cathodes and GDC electrolyte performed comparable to typical Ni-GDC anodes with hydrogen fuel at 750°C (Figure 1). LSCM-GDC-Ni anodes with propane fuel at 750°C exhibited performance superior to Ni-GDC anodes without evidence of carbon formation (SEM/EDX analysis), after 3 hours continuous operation (Figure 2). Methane utilization has also been demonstrated under similar conditions. The unique anodes provide a SOFC system capable of directly converting a variety of hydrocarbons efficiently, without chemical reforming, and offering significant economic potential.
STATUS: A patent application has been filed.
Inventor(s): Scott A. Barnett, Jiang Liu, Brian Madsen, John Ji
Type of Offer: Licensing
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