CATALYTIC ANODES FOR THE DIRECT OXIDATION OF HYDROCARBONS IN SOLID OXIDE FUEL CELLS
Dr. John M. Vohs
Department of Chemical Engineering
University of Pennsylvania
Wednesday, January 16, 2002 at 4:00PM
University of Kentucky's Hilary J. Boone Jr. Faculty Club
Fuel cells have the potential to provide a highly efficient and environmentally friendly means to generate electricity for a variety of applications. The widespread use of fuel cells, however, has been hampered by the fact that most designs require that hydrogen, which is difficult to generate and store, be used as the fuel.
A fuel cell that relies on the direct, electrochemical oxidation of readily available hydrocarbon fuels, such as gasoline or diesel, to produce electrical power would clearly have significant advantages over systems that operate only on hydrogen. Solid oxide fuel cells (SOFC) which make use of an oxygen ion-conducting electrolyte and operate at high temperatures are one technology that have shown some promise for the direct utilization of hydrocarbon fuels. Although it is possible to operate a conventional SOFC on hydrocarbons the cell rapidly deactivates due to carbon deposition on the anode.
In this talk I will give an overview of our research program on the development of anodes for SOFCs that circumvent this problem and are active for the direct electrochemical oxidation of methane, higher hydrocarbons, and complex hydrocarbon mixtures such as gasoline and diesel. Our approach relies on the synthesis of a highly porous and thermally stable ceramic anode matrix in which both metallic and oxide components can be deposited using wet impregnation techniques. This design provides a high degree of flexibility in optimizing the catalytic properties of the anode.
Results will be presented which demonstrate that copper-based anodes that incorporate catalytically active oxides, such as ceria, are active for the direct electrocatalytic oxidation of a wide range of hydrocarbons including alkanes, alkenes, and aromatics and are not susceptible to deactivation via carbon deposition.