This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Influence of Phosphorus on Three-Component Control Catalysts: Catalyst Durability and Characterization Studies
Annotation ability available
Sector:
Language:
English
Abstract
A study has been conducted Co investigate the effect of phosphorus derived from zinc dialkyldithiophosphate (ZDP) on monolithic, three-component control catalyst durability. The objectives were to identify the extent of phosphorus induced deactivation, identify the form (s) of the phosphorus species responsible for the poisoning and study reactivation of the poisoned catalysts by thermal treatments. Catalysts were aged on an engine dynamometer for 200 hours. The experiments included accelerating oil usage by removing either the intake or exhaust valve seals and doping the oil with excess ZDP. Dynamometer evaluations show that catalysts exposed to oil (accelerated leakage through the intake or exhaust valves) with a phosphorus content of 0.7 wt. % have considerably poorer activity than a base line catalyst with very little oil exposure. Laboratory evaluations indicate that 0.4 wt. % phosphorus on the catalyst is enough to cause a significant loss in activity while additional phosphorus has only a slight effect. Attempts to reactivate the phosphorus poisoned catalysts under lean and rich synthetic exhaust conditions at temperatures as high as 760°C did not succeed.
No crystalline zinc phosphorus compounds were detected by X-ray diffraction. SEM analyses of the engine aged catalysts show the presence of amorphous zinc phosphorus compounds largely on the surface of the support. The zinc phosphorus compounds found on the catalyst engine aged with intake valve seals removed are different from those found on the catalyst engine aged with exhaust valve seals removed. It also appears that species other than zinc pyrophosphates are present and are at least partially responsible for catalyst deactivation. Finally, pore plugging is observed and accounts for some of the deactivation.
Recommended Content
Authors
Citation
Joy, G., Molinaro, F., and Homeier, E., "Influence of Phosphorus on Three-Component Control Catalysts: Catalyst Durability and Characterization Studies," SAE Technical Paper 852099, 1985, https://doi.org/10.4271/852099.Also In
References
- Caracciolo Frank Spearot James A “Engine Oil Additive Effects on the Deterioration of a Stoichiometric Emissions Control (C-4) System” SAE Paper 790941
- Shelef, M. Otto K. Otto N. C. “Poisoning of Automotive Catalyst” Advances in Catalysis 27 311 1978
- a) Korcek, Stephen Mahoney, L. R. Johnson, M. D. Siegel, W. O. “Mechanise of Antioxidant Decay in Gasoline Engines. Invesitgation of Zinc Dialkyldithiophosphate Additives” SAE 810014 b) Jentsh, C. Goers G. Klosterman W. “The Role of Zinc Dialkydithiophosphtes” Erdoel Kohle, Erdgas, Petrochem. Brennst. - Chem. 33 1976 c) Spedding, H Watkins R. C. “The Antiwear Mechanism of Zinc Dialkyldithiophosphates” Trebol 15 9 12 1982
- Shellef, M. Betta, R. A. Dalla Larson J. A. Otto K. Yao H. C. “Poisoning of Monolithic Noble Metal Oxidation Catalysts on Automobile Exhaust Environment” Paper 78A presented to the American Institute of Chemical Engineers, New Orleans Meeting 1973
- Kim, G. W. Ernest M. V. Montgomery. S. R. “Deactivation of Pelleted Three-Way Catalysts. Post-Mortem Studies” Ind. Eng. Chem. Prod. Res. Dev. 23 525 532 1984
- Minamitani, Hiromu Ikuyama, A. Machida, C. Kawashima, K. Matsudaira Y. Furui J. “Effects of Engine Oil Additives on Activity of Exhaust Gas Oxidation Catalysts” J. Japan Petroleum Institute 21 116 120 1978
- Gandhi, H. S. Williamson W. B. Bomback. J. L “Deactivation of Three-Way and Oxidation Catalyst Dual-Bed Emission Control Systems; Catalyst Post-Mortem Analyses from Methanol Fueled Vehicles” Applied Catalysis 3 79 88 1982
- Williamson, W. B. Perry, J. Gandhi H. S. Beason. R. E. “Catalyst Deactivation due to Glaze Formation from Oil Derived Phosphorus and Zinc” SAE Paper 841406
- Kirchner K. et al “Poisoning of Noble Metal Catalysts by Phosphorus Compounds” Parts I-III Chem. Eng. Sci. 35 2089 2105 1980
- Williamson, W. B. Perry, J. Gandhi H. S. Bomback. J. L. “Effects of Oil Phosphorus on Deactivations of Monolithic Three-Way Catalyst” Applied Catalysis 15 277 292 1985
- Caracciolo, F. Spearot. J. A. “The Effects of Phosphorus-Containing Engine Oil Additives on Exhaust Oxidation Catalyst Degradation” SAE Paper 760562
- Lester G. R. Marinangeli. R. E. “Production of Relative Poison Sensitivities of Conventional and Pelleted Monolithic Automotive Catalysts” SAE Paper 800844
- Joy, G. C. Lester G. R. Molinaro. F. S. “Influence of Sulfur Species on the Laboratory Control of Automotive Three Component Control Catalysts” SAE Paper 790943
- Thiolo Erich Grunze Ingrid “The Chemistry of Condensed Phosphates and Arsenates XVI” Z. anorg. allg. Chem. 290 223 1957
- Gemlin 68 133