Investigation of Boudouard Reactions on Carbon-based Solid Oxide Fuel Cells by Transient Techniques

Carbon-based solid oxide fuel cell (C-SOFC) is an effective approach for electric power generation because of its simplicity. The basic principle of the carbon-based fuel cell is electrochemical oxidization of solid carbon to CO2 on the anode. CO2 produced can further react with carbon fuel to generate CO via Boudouard reactions (C+CO2 -> 2CO). Transient techniques consisting of pulse injection and step switch were used to study Boudouard reaction on C-SOFCs. The step switch and pulse transient studies showed that up to 90% of CO2 can be converted to CO, which was involved in electrochemical oxidation to increase power densities. The contribution of CO to increased power densities was confirmed by separating solid carbon and fuel cells in varying flow patterns. CO2 and CO were also found to displace adsorbed H-2 on carbon fuels. The desorbed H-2 was then oxidized to produce H2O on C-SOFCs.