Electrochemical DeNOX in solid electrolyte cells - an overview

The investigations in the field of electrochemical reduction of nitric oxide are reviewed. Using a cell based on an oxide ionic conductor it is shown that the selectivity and activity of the cathodes is strongly dependent on the temperature and of the composition of the cathode material. In general the selectivity is highest at the lowest temperatures. Cathode materials with a high redox capacity are shown to have the highest performance towards the reduction of nitric oxide. Different approaches using a protonic conductor are also reviewed. In the end a few examples of the electrochemical promotion of the reduction of nitric oxide with a reducing agent are given. Literature reveals that electrochemical promotion of the reduction of nitric oxide with a reducing agent is possible also under lean conditions. The electrochemical promotion is accompanied by an increase in the selectivity towards the formation of nitrogen. (c) 2004 Published by Elsevier B.V.