Nitric oxide removal from simulated lean-burn engine exhaust using a solid oxide fuel cell with V-added (LaSr)MnO3 cathode

A solid oxide fuel cell (SOFC) unit cell is constructed by coating V-added La0.8Sr0.2MnO3–Ce0.9Gd0.1O2 as the cathode onto a disk of anode-supported bilayers of yttria-stabilized zirconia (YSZ) and Ni-YSZ. Various compositions of lean-burn engine exhaust components of O2, H2O, CO2 and NO were tested over the cathode of SOFC unit cell operating at 700–800 °C. NO can be completely converted to N2. All the exhaust components have beneficial effect on NO conversion. Increasing O2 content from 2 to 10% increases NO conversion from 18% to about 70%; this enables us to increase the O2 content by adding air in the exhaust to increase the NO conversion. Increasing NO concentration increases NO conversion. Adding H2O, increasing CO2 content and an increase of the generated voltage all increase NO conversion, although only slightly. These are beneficial for the application of SOFCs to NO removal from lean-burn engine exhaust.