1. The Role of Catalysis in Next Generation Direct Hydrocarbon Solid Oxide Fuel Cell Anodes
Steven McIntosh, Department of Chemical Engineering, University of Virginia
LSCM, CH4:
973K (solid)
1073K (dashed).
Solid Oxide Fuel Cells (SOFCs) are considered one of the most promising candidates for efficient future power generation. As SOFC operate via transport of oxygen anions from the air electrode (cathode) to the fuel electrode (anode), SOFC can theoretically operate on a wide range of fuels. A number of groups are researching the oxygen anion and electronic conductivity of potential oxide anode materials; we have focused on their catalytic activity for fuel oxidation. We investigated the role of oxygen non-stoichiometry, δ, on the activity and selectivity of the promising anode material La0.75Sr0.25CrxMn1-xO3-δ (LSCM) towards total oxidation of hydrocarbon fuels under SOFC anode conditions. We find that both activity and total oxidation selectivity decrease with increasing non-stoichiometry due to reduction of the oxygen available for reaction. We have utilized electrochemical testing of LSCM-based SOFC anodes to link the oxygen stoichiometry dependant catalytic properties to the non-linear response of the electrode to increasing current density (oxygen ion flux).
SOFC resistance LSCM-based anode
CH4 fuel, 973K
Increasing current