Electrochemical Removal of NOx on Ceria-Based Catalyst-Electrodes.

This study reports the electrochemical properties for NOx reduction of a ceria-based mixed ionic electronic conducting porous electrode promoted by Pt nanoparticles, as efficient catalyst for NO oxidation, and BaO, as sorbent to store NO_x. This catalytic layer was deposited by screen-printing on a dense membrane of gadolinia-doped ceria, an O^2- ionic conductor. The targeted Ba and Pt loadings were 150 and 5 5 μg/cm², respectively. The NOx selective electrochemical reduction was performed between 400 °C and 500 °C with and without oxygen in the feed. Variations of the open-circuit voltage with time were found to be a good sensor of the NOx storage process on the ceria-based catalyst-electrode. However, no N₂ production was observed in the presence of O₂ phase in spite of nitrates formation. [ABSTRACT FROM AUTHOR]