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Further Analysis of the Effect of Oxygen Concentration on the Thermal Aging of Automotive Catalysts
ISSN: 0148-7191, e-ISSN: 2688-3627
Published September 04, 2017 by SAE International in United States
This content contains downloadable datasetsAnnotation ability available
With emission legislations becoming ever more stringent there is an increased pressure on the after-treatment systems, and more specifically the three-way catalysts. With recent developments in emission legislations, there is requirement for more complex after-treatment systems and understanding of the aging process. With future legislation introducing independent inspection of emissions at any time under real world driving conditions throughout a vehicle life cycle this is going to increase the focus on understanding catalyst behavior during any likely conditions throughout its lifetime and not just at the beginning and end.
In recent years it has become a popular approach to use accelerated aging of the automotive catalysts for the development of new catalytic formulations and for homologation of new vehicle emissions. To accelerate the catalyst aging, the samples experience high temperatures of 800°C and higher on a recognized aging cycle for a specific time which can be related back to vehicle mileage. As opposed to using large gasoline engines, alternative bench-aging techniques are becoming more frequently used, including synthetic gas bench reactors. Bench reactors offer more flexibility, greater repeatability and opportunity for more precise control over variables providing greater development possibilities.
Whilst the body of understanding on catalyst deactivation and, in particular, catalyst aging is growing, there are still significant gaps in understanding, particularly how real world variations in temperature, flow rate and gas concentrations affect catalyst behavior.
Under normal driving conditions the catalyst can experience varying oxygen concentrations, such as under heavy acceleration or cruising down a hill will show a variation in oxygen from the engine emissions. The effect of varying oxygen concentrations has on the rate of aging is not fully understood and hence the total deactivation and efficiencies are not known throughout the catalyst lifetime. Current algorithms used in industry do not fully account for these variations in oxygen concentrations.
This paper presents a continuation of previous work into the investigation of the effect of varying oxygen concentration on the rate of catalyst aging. A number of commercially available palladium three-way catalysts were aged over a precise temperature cycle at varying oxygen concentrations for different aging times related back to a mileage. The results were analyzed in detail and compared with predictions based on the standard aging algorithm and with others proposed in literature.
CitationIrwin, K., Douglas, R., Stewart, J., Pedlow, A. et al., "Further Analysis of the Effect of Oxygen Concentration on the Thermal Aging of Automotive Catalysts," SAE Technical Paper 2017-24-0136, 2017, https://doi.org/10.4271/2017-24-0136.
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- Argyle M, Bartholomew C. Heterogeneous Catalyst Deactivation and Regeneration: A Review. Catalysts. 2015;5:145-269.
- Bartholomew CH. Mechanisms of catalyst deactivation. Appl Catal A Gen. 2001;212[1-2]:17-60.
- Heck RM, Farrauto RJ, Gulati ST. Catalytic Air Pollution Control: Commercial Technology: Third Edition. Catalytic Air Pollution Control: Commercial Technology: Third Edition. John Wiley and Sons; 2012.
- Nagashima K, Zhang G, Hirota T, Muraki H. The Effect of Aging Temperature on Catalyst Performance of Pt/Rh and Pd/Rh TWCs. 2000;:10.
- González-velasco JR, Botas JA, Ferret R, González-marcos MP, Marc J, Gutiérrez-ortiz MA. Thermal aging of Pd / Pt / Rh automotive catalysts under a cycled oxidizing - reducing environment. 2000;59:395-402.
- Heck RM, Farrauto RJ, Gulati ST. Catalytic air pollution control: commercial technology. Vol. 5. John Wiley & Sons; 2009.
- Härkönen M, Kivioja M, Lappi P, Mannila P, Maunula T, Slotte T. Performance and Durability of Palladium Only Metallic Three-Way Catalyst. 1994;.
- More KL, Kenik EA, Coffey DW, Geer TS, Labarge WJ, Beckmeyer R, et al. Thermally-Induced Microstructural Changes in a Three-Way Automotive Catalyst. 1997;.
- Moldovan M, Rauch S, Morrison GM, Góez M, Antonia Palacios M. Impact of ageing on the distribution of platinum group elements and catalyst poisoning elements in automobile catalysts. Surf Interface Anal. 2003;35:354-9.
- Martín L. Simulation three-way catalyst ageing Analysis of two conventional catalyst. Appl Catal B Environ. 2003;44:41-52.
- Usmen. Techniques for Analyzing Thermal Deactivation of Automotive Catalusts. 1992;
- He Z, Shao Q, Li Y, Jing Z, Duan Q. Study on the Aging Test Methods and the Properties of the Three-Way Catalysts. 2003.
- Zotin FMZ, Da Fonseca Martins Gomes O, De Oliveira CH, Neto AA, Cardoso MJB. Automotive catalyst deactivation: Case studies. Catal Today. 2005;107-108:157-67.
- Winkler A, Ferri D, Hauert R. Influence of aging effects on the conversion efficiency of automotive exhaust gas catalysts. Catal Today. Elsevier B.V.; 2010;155[1-2]:140-6.
- Fernandes DM, Scofield CF, Neto AA, Cardoso MJB, Zotin FMZ. The influence of temperature on the deactivation of commercial Pd/Rh automotive catalysts. Process Saf Environ Prot. 2009;87[October 2008]:315-22.
- Zheng Q, Farrauto R, Deeba M. Part II: Oxidative Thermal Aging of Pd/Al2O3 and Pd/CexOy-ZrO2 in Automotive Three Way Catalysts: The Effects of Fuel Shutoff and Attempted Fuel Rich Regeneration. Catalysts. 2015;5:1797-814.
- González-Velasco JR, Botas J a., Ferret R, Pilar González-Marcos M, Marc J-L, Gutiérrez-Ortiz M a. Thermal aging of Pd/Pt/Rh automotive catalysts under a cycled oxidizing-reducing environment. Catal Today. 2000;59[3-4]:395-402.
- Chen X, Cheng Y, Seo CY, Schwank JW, McCabe RW. Aging, re-dispersion, and catalytic oxidation characteristics of model Pd/Al2O3 automotive three-way catalysts. Appl Catal B Environ. Elsevier B.V.; 2015;163:499-509.
- Fernandes DM, Alcover Neto A, Cardoso MJB, Zotin FMZ. Commercial automotive catalysts: Chemical, structural and catalytic evaluation, before and after aging. Catal Today. 2008;133-135:574-81.
- Environmental Protection Agency. Federal Register, Part IV, Emission Durability Procedures and Component Durability Procedures for New Light Duty Vehicles, Light Duty Trucks and Heavy Duty Vehicles; Final Rule and Proposed Rule. 2006;1-34.
- US EPA OOI. Clean Air Act Requirements and History.
- Baba, N., Yokota, K., Matsunaga, S., Kojima, S. et al., "Numerical Simulation of Deactivation Process of Three-way Catalytic Converters," SAE Technical Paper 2000-01-0214, 2000, doi:10.4271/2000-01-0214.
- Blades L. Faculty of Engineering & Physical Sciences School of Mechanical and Aerospace Engineering Ageing Mechanisms in Automotive Catalysts. 2015.
- Woods AJ. Ageing and Characterisation of Automotive Catalysts by. 2007.
- Stewart JD, Stalker RM, Shaughnessy RO, Douglas R, Woods A. Sensitivity Analysis of Full Scale Catalyst Response under Dynamic Testing Conditions - A Method to Develop Further Understanding of Catalytic Converter Behavior Pt . 1. 2016;
- McAtee C, McCullough G, Douglas R, Glover L. The Effect of De-Greening and Pre-Treatment on Automotive Catalyst Performance. 2011;
- Irwin KJ, Stewart J, Douglas R, Woods A, Shaughnessy RO, Pedlow A, et al. Analysis of the Effect of Oxygen Concentration on the Thermal Aging of Automotive Catalysts. 2017;