Electrochemical activation of Pt–Ba/YSZ NOxTRAP catalyst under lean-burn conditions

The NOx abatement efficiency of an electrochemical NOxTRAP catalyst Pt–Ba/YSZ was investigated at 500 °C with different oxygen partial pressures in the storage phase. Cathodic polarization was found to promote the NOx storage capacity even under lean-burn conditions. The duration until full NOx storage was drastically increased by ~ 80 s in the presence of 6% of oxygen. During regeneration phases, NO electrochemical reduction occurs and can remove ~ 10% of NOx. Electrochemical activation of the NOx storage capacity was linked with the generation of oxygen vacancies on the YSZ surface induced by negative polarization.

► NOxTRAP electrochemical catalyst Pt–Ba/YSZ.
► NOx storage capacity electropromoted under lean-burn conditions.
► Electrochemical activation of NOx storage linked with oxygen vacancies.