Transactions of the Korean Society of Automotive Engineers (한국자동차공학회논문집)

The Korean Society of Automotive Engineers (한국자동차공학회)
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Aging Characteristics of NOx Storage and Reduction Catalyst for Lean-bum Natural Gas Vehicles

린번 천연가스자동차용 NOx 흡장촉매의 열화특성

  • Published : 2007.05.01
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Abstract

This study investigates the aging characteristics of NOx storage and reduction(NSR) catalyst on the emission conditions of lean burn natural gas vehicles. We designed various NSR catalysts using by the double-layer washcoat technology to increase of a surface area and a thermal durability performance of the catalysts. The experiments were conducted with 3 kinds of the NSR catalysts, which were manufactured using by a honeycomb cordierite substrate. It was found that Ba is weak in the thermal aging because it has lower melting temperature than that of precious metals (PMs). The suitable loading amount of Ba in this study should be about 42 g/L from the results of the NOx adsorption and the NOx reduction efficiency. The major reason in deactivation of the NSR catalyst is the decrease of the adsorption site owing to the agglomeration and sintering of Ba rather than PM aging by hydrothermal aging. It was confirmed by results of BET, SEM and TEM.

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References

  1. M. S. Brogan, R. J. Brisley, A. P. Walker, D. E. Webster, W. Boegner, N. P. Fekete, M. Kramer, B. Krutzsch and D. Voigtlander, 'Evaluation of NOx Storage Catalysts as an Effective System for NOx removal from the Exhaust Gas of Lean-burn Gasoline Engine,' SAE 952490, 1995
  2. B. C. Choi, W. N. Juhng and C. H. Lee, 'Comparison of NOx Reduction Characteristics of NOx Storage Catalyst and TWC for Lean-burn Natural Gas Vehicles,' Transaction of KSME, Vol.12, No.5, pp.79-84, 2004
  3. C. H. Lee and B. C. Choi, 'Evaluation of NOx Reduction Catalyst by Model Gas for Leanburn Natural Gas Engine,' Int. J. Automotive Technology, Vol.6, No.6, pp.591-598, 2005
  4. C. H. Lee and B. C. Choi, Reduction Characteristics of NOx Storage Catalyst for Lean-burn Natural Gas Vehicles, The 18th Internal Combustion Engine Symposium(International), Paper No. 20056052, 2005
  5. N. Miyoshi, S. Matsumoto and K. Katoh, 'Development of New Concept Three-way Catalyst for Automotive Lean-burn Engines,' SAE 950809, 1995
  6. N. Takahashi, H. Shinjoh and T. Iijima, 'The New Concept 3-way Catalyst for Automotive Lean-burn Engine: NOx Storage and Reduction Catalys,' Catalysis Today, Vol.27, pp.63-69, 1996 https://doi.org/10.1016/0920-5861(95)00173-5
  7. S. Matsumoto, Y. Ikeda, H. Suzuki, M. Ogai and N. Miyoshi, 'NOx Storage-reduction Catalyst for Automotive Exhaust with Improved Tolerance against Sulfur Poisoning,' Applied Catalysis B: Environmental, Vol.25, pp.115-124, 2000 https://doi.org/10.1016/S0926-3373(99)00124-1
  8. L. Castoldi, I. Nova, L. Lietti and P. Forzatti, Study of Effect of Ba Loading for Catalytic Activity of $Pt-Ba/Al_2O_3$ Model Catalysts, Catalysis Today, Vol.96, pp.43-52, 2004 https://doi.org/10.1016/j.cattod.2004.05.006
  9. B. C. Choi, J. W. Jung, G. S. Son and M. G. Jung, Characteristics of Rh-Pd-Pt TWC with Double-Layer Washcoat on the Hydrothermal Aging, Transaction of KSME, Vol.14, No.1, pp.8-16, 2006
  10. E. Fridell, H. Persson, B. Westerberg, S. Johansson and G. Smedler, 'NOx Storage in Barium-Containing Catalysts,' Journal of Catalysis, Vol.183, No.2, pp.196-209, 1999 https://doi.org/10.1006/jcat.1999.2415
  11. F. Rodrigues, L. Juste, C.Potvin, J. F. Tempere, G. Blanchard and G. Djega-Mariadassou, 'NOx Storage on Barium-containing There-way Catalyst in the Presence of $CO_2$,' Catalysis Letters, Vol.72, No.59, pp.59-64, 2001 https://doi.org/10.1023/A:1009001630673
  12. J. R. Theis, J. A. Ura and G. W. Graham, 'The Effects of Aging Temperature and Air-fuel Ratio on the NOx Storage Capacity of a Lean NOx Trap,' SAE 2004-01-1493, 2004