Electrochemical removal of NOx with porous cell stacks

In this study porous cell stacks were investigated for their ability to remove NOx electrochemically. The cell stacks were made from laminated tapes of porous electrolyte Ce0.9Gd0.1O1.95 and composite electrodes of La1−xSrxMnO3 (x = 0.15, and 0.5) and ceria doped with Gd or Pr. The cell stacks were infiltrated with nano-particles of pure ceria, Ce0.9Gd0.1O1.95 and Ce0.8Pr0.2O2−δ after sintering. A gas stream containing NO were sent through the cell stack. When the cell stacks were polarised with 0.75 V per cell then it was possible to remove some of the NOx in the temperature interval of 250–400 °C. The cell stacks infiltrated with ceria showed the highest activity, while the ones infiltrated with Ce0.9Gd0.1O1.95 had the highest selectivity towards NO compared to O2. When the cell stack was polarised with 1.5 V for each cell it was possible to remove up to 35% of NO present.