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Performance of a Stabilized Ruthenium NOx Reduction Catalyst
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English
Abstract
MgO has been found to stabilize Ru against volatilization and agglomeration under oxidizing conditions at temperatures up to 850°C (1560°F). However, before MgO stabilized Ru can be used as an automotive NOx reduction catalyst, it must be put in a form compatible with conditions in the exhaust system. This can be done by impregnating a cordierite honeycomb, which has been washcoated first with high surface area alumina then with MgO, with Ru. Such catalysts were tested under both engine dynamometer and vehicle conditions. Good activity maintenance was found in engine dynamometer tests, but activity was lost rapidly in the vehicle tests. This rapid loss of activity was probably caused by exposure of the catalyst to surface temperatures which exceed the temperature stability limit (∼900°C) of the RuO2-MgO surface bond in current versions of this catalyst. Such temperatures could be encountered on the AMA durability cycle used in the vehicle aging of these catalysts.
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Authors
Citation
Pepper, M., DeLuca, J., Rohdes, R., and Bernstein, L., "Performance of a Stabilized Ruthenium NOx Reduction Catalyst," SAE Technical Paper 750684, 1975, https://doi.org/10.4271/750684.Also In
References
- Bernstein L. S. et al. “Application of Catalysts to Automotive NO x Emission Control” SAE Trans. 80 42 62 1971
- Lunt R. S. et al. “Application of Monel-Platinum Dual-Catalyst System to Automotive Emission Control” SAE Trans. 81 810 29 1972
- Bernstein L. S. et al. “Nickel-Copper Alloy NO x Reduction Catalysts For Dual Catalyst Systems” SAE Paper 730567 National Automobile Engineering Meeting Detroit, Michigan May 1973
- Lang R. J. et al. “Factors Affecting Dual Catalyst System Performance” SAE Paper 740252 Automotive Engineering Congress Detroit, Michigan February 1974
- Shelef M. Gandhi H. S. “Ammonia Formation in Catalytic Reduction of Nitric Oxide by Molecular Hydrogen II Noble Metal Catalysts” Ind. and Eng. Chemistry, Prod. Res. and Dev. 11 393 96 1972
- Klimisch R. L. Taylor K. C. “The Catalytic Reduction of Nitric Oxide Over Supported Ruthenium Catalysts” Journal of Catalysis 30 478 484 1973
- Shelef M. Gandhi H. S. “The Reduction of NO in Automobile Emissions Stabilization of Catalysts Containing Ruthenium” Platinum Metals Review 18 2 1974
- Kobylinski T. P. Taylor B. W. “Stabilized Ru Catalysts for NOx Reduction” SAE Paper 740250 Automotive Engineering Congress Detroit, Michigan February 1974
- Gandhi H. S. et al. “Durability Testing of Stabilized Ru-Containing Catalysts” SAE Paper 750177 Automotive Engineering Congress Detroit, Michigan February 1975