Catalysis Letters

, Volume 77, Issue 1, pp 21–28

Deterioration Mode of Barium-Containing NOx Storage Catalyst

Authors

  • Bo-Hyuk Jang
    • School of Chemical EngineeringAjou University
  • Tae-Hun Yeon
    • School of Chemical EngineeringAjou University
  • Hyun-Sik Han
    • Heesung Engelhard Co.
  • Yong-Ki Park
    • Korea Research Institute of Chemical Technology
  • Jae-Eui Yie
    • School of Chemical EngineeringAjou University
Article

DOI: 10.1023/A:1012759716973

Cite this article as:
Jang, B., Yeon, T., Han, H. et al. Catalysis Letters (2001) 77: 21. doi:10.1023/A:1012759716973
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Abstract

Barium-containing NOx storage catalyst showed serious deactivation under thermal exposure at high temperatures. To elucidate the thermal deterioration of the NOx storage catalyst, four types of model catalyst, Pt/Al2O3, Ba/Al2O3, Pt–Ba/Al2O3, and a physical mixture of Pt/Al2O3 + Ba/Al2O3 were prepared and their physicochemical properties such as BET, NO TPD, TGA/DSC, XRD, and XPS were evaluated while the thermal aging temperature was increased from 550 to 1050°C. The fresh Pt–Ba/Al2O3 showed a sorption capacity of 3.35 wt%/g-cat. but the aged one revealed a reduced capacity of 2.28 wt%/g-cat. corresponding to 68% of the fresh one. It was found that this reduced sorption capacity was directly related to the deterioration of the NOx storage catalyst by thermal aging. The Ba on Ba/Al2O3 and Pt–Ba/Al2O3 catalysts began to interact with alumina to form Ba–Al solid alloy above 600°C and then transformed into stable BaAl2O4 having a spinel structure. However, no phase transition was observed in the Pt/Al2O3 catalyst having no barium component, even after aging at 1050°C.

NOx storage catalystdeactivation modePt–Ba/Al2O3BaAl2O4

Copyright information

© Plenum Publishing Corporation 2001