A study of the behaviour of Pt supported on CeO2-ZrO2/Al2O3-BaO as NOx storage-reduction catalyst for treatment of lean burn engine emissions

The behaviour of a Pt(1 wt.%) supported on CeO2-ZrO2(20 wt.%)/Al2O3(64 wt.%)-BaO(16 wt.%) as a novelNOx storage- reduction catalyst is studied by reactivity tests and DRIFT experiments and compared with that of Pt(1%)-BaO(15 wt.%) on alumina. The former catalyst, designed as a hydrothermally stable sample, is composed of an alumina modified with Ba ions and an overlayer of ceria-zirconia. The results pointed out that during the calcination barium ions migrates over the surface of the catalyst which thus show a good NOx storage-reduction behaviour comparable with that of Pt-BaO on alumina, although Ba ions result much better dispersed.