| 1. |
- Fridell, Erik, 1963, et al.
(författare)
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Model studies of NOx storage
- 2001
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Ingår i: ENVICAT2001, Amolfi, Italy, May 2-6, 2001.
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Konferensbidrag (refereegranskat)
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| 2. |
- Fridell, Erik, 1963, et al.
(författare)
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Model studies of NOx storage and sulphur deactivation of NOx storage catalysts
- 2001
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Ingår i: Topics in Catalysis. - 1572-9028 .- 1022-5528. ; 16-17:1-4, s. 133-137
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Tidskriftsartikel (refereegranskat)abstract
- The storage of NOx under lean conditions in model NOx storage catalysts as well as the deactivation by sulphur have been studied. We find that NO2 plays an important role in the storage mechanism as an oxidising agent. Two different mechanisms for this are discussed: the formation of surface peroxides and the oxidation of nitrites to nitrates, FTIR studies show that NOx is stored as surface nitrates, The sulphur deactivation is found to be more severe when SO2 is added during the rich phase than when SO2 is added during the lean period. FTIR shows the formation of bulk sulphates both under lean and rich conditions.
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| 3. |
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| 4. |
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| 5. |
- Fridell, Erik, 1963, et al.
(författare)
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The Mechanism for NOx Storage
- 2000
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Ingår i: Catalysis Letters. - 1572-879X .- 1011-372X. ; 66:1-2, s. 71-74
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Tidskriftsartikel (refereegranskat)abstract
- The mechanisms for storing of NOx in platinum-barium-alumina catalysts during lean-rich transients are investigated. Oxidation of NO to NO2 is found to be an important step. NO2 is found to be important for oxidation of the catalyst or of nitrites to form nitrates. NOx is then stored in the form of surface nitrates. FTIR studies show no formation of bulk nitrates in these experiments.
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| 6. |
- Olsson, Louise, 1974, et al.
(författare)
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A kinetic study of oxygen adsorption/desorption and NO oxidation over Pt/Al2O3 catalysts
- 1999
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Ingår i: Journal of Physical Chemistry B Materials. - : American Chemical Society (ACS). - 1089-5647 .- 1520-6106 .- 1520-5207. ; 103:47, s. 10433-10439
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Tidskriftsartikel (refereegranskat)abstract
- Laboratory tests and kinetic modeling were carried out in order to provide kinetic input data to a systematic investigation of the mechanism of nitrogen oxides (NO,) storage in catalysts used for lean-burn engines. In particular, we present a kinetic model of the NO oxidation to NO2 over a Pt/Al2O3 model catalyst for the temperature range 250-450 degrees C. Since the oxygen behavior at atmospheric pressure is critical for such a model, we have also studied the adsorption/desorption of oxygen by temperature-programmed desorption (TPD) experiments. The experiments show that oxygen starts to desorb at about 300 degrees C. Furthermore, the NO oxidation was studied in a temperature ramp with NO and oxygen in the gas feed. The data from this experiment and the above-determined values for the oxygen adsorption/desorption were used to construct a kinetic model for the NO oxidation. Finally, the model was validated with some transient experiments with either NO or NO2 and different oxygen concentrations in the gas feed. We found a good agreement between these experiments and the model.
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| 7. |
- Skoglundh, Magnus, 1965, et al.
(författare)
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Model studies of NOx storage catalysts
- 2000
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Ingår i: 2000 International Chemical Congress of Pacific Basin Societies (PACIFICHEM’2000) in Honolulu, Hawaii, USA, December 14-19, 2000..
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Konferensbidrag (refereegranskat)
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