Electrochemical NOx Reduction with Power Generation in Solid Oxide Fuel Cells with Cu-Added (LaSr)(CoFe)O-3-(Ce,Gd)O2-x Cathode

A process for nitric oxides (NOx, NO plus NO2) removal by solid oxide fuel cells (SOFCs) can easily reduce NOx in the flue gases to zero and also generate an electrical current. An yttria-stabilized zirconia electrolyte-supported SOFC unit cell was constructed with Ni-gadolinia-doped ceria (GDC) as the anode and Cu-added La0.58Sr0.4Co0.2Fe0.8O3-delta-GDC composite as the cathode. DeNO(x) tests were carried out at a fixed voltage of 0.55 V and 800 degrees C. As the inlet NOx concentration decreases, the NOx conversion increases. The generated current density increases with increasing NO concentration from 150 to 5000 ppm. Increasing O-2 concentration from 4 to 8% increases the NO conversion due to increased current density, which increases the oxygen transfer rate. Adding CO2 can increase the NO conversion, and also due to increased current density. As the O-2 concentration increases from 2 to 8% and the CO2 concentration increases from 5 to 15%, the generated current density increases. Adding H2O can decrease both the current density and the NO conversion.