Effect of H2O and CO2 on NOx emission control for lean-burn engines by electrochemical-catalytic cells

Lean-burn engines can offer superior fuel efficiency but require advanced technology for NOx emission control. Electrochemical-catalytic cell has been proposed for lean DeNOx. This work demonstrates that the DeNOx rate can be enhanced by the presence of H2O and/or CO2, and can increase with increasing H2O and CO2 concentrations, although the increased extent is quite small. In the low NOx concentration range, relatively constant DeNOx rates were observed and can result in zero NOx emissions, where the presence of H2O and CO2 has important enhancement effect. Higher temperature generally results in larger N2 selectivity in the low NOx concentration region.