The NOx Storage and Resistance of SO2 Poison on the BaCeO3 Perovskite Type Oxides

The BaCeO3perovskite type samples are prepared by the improved sol-gel method. Besides, the Pt/BaCeO3, Rh/BaCeO3, Pt-Rh/BaCeO3and the Pt/BaCeO3/γ-Al2O3, Rh/BaCeO3/γ-Al2O3, Pt-Rh/BaCeO3/γ-Al2O3are also prepared. The results showthat adding precious metals, the NSC of the BaCeO3samples decrease. The sequence ofNSC is the Pt>Rh>Pt-Rh. Adding onlyγ-Al2O3has no effect on the NSC of the BaCeO3sample. However, the NSC of Pt/BaCeO3/γ-Al2O3sample increases more than three times as much as that of the BaCeO3/γ-Al2O3. The reason of the Nox storage enhancement by adding precious metals is discussed. Combining with XRD analysis, the perovskite type of BaCeO3is the main active phase ofNOxstorage forthe Ba-Ce-Osample. The results also indicate thatthe BaCeO3and Pt/BaCeO3samples keep the ability to resist poison produced by SO2at≤0. 006% SO2, and the Pt/BaCeO3/γ-Al2O3 sample possesses not only high capacity of NOxstorage but also high ability to resist poison produced by SO2.