An experimental and kinetic modeling study of aging impact on surface and subsurface oxygen storage in three-way catalysts
| Autor: | Jian Gong, Aleksey Yezerets, Di Wang, Junhui Li, Krishna Kamasamudram, Neal W. Currier |
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| Rok vydání: | 2019 |
| Předmět: |
Materials science
Oxygen storage Kinetics 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology Kinetic energy 01 natural sciences Oxygen storage capacity Catalysis 0104 chemical sciences Reaction rate constant Chemical engineering Three way 0210 nano-technology |
| Zdroj: | Catalysis Today. 320:51-60 |
| ISSN: | 0920-5861 |
| Popis: | The aging impact on oxygen storage capacity (OSC) of three-way catalyst was investigated through experiments and modeling. OSC measurements were conducted on two commercial TWCs (one fresh and one aged) over the temperature window of 100–600 °C. The amount of OSC decreased by 44% at 400 °C and the kinetic restrictions of OSC reductions extended towards higher temperatures after standard bench cycle (SBC) aging at 955 °C for 57 h. The relationship between OSC and temperature was modified. Dynamic OSCs (breakthrough OSC and sub-surface OSC) on the fresh and aged TWCs were predicted with a dual-site OSC model. From the modeling results, we found that not only the quantities of oxygen storage sites decreased but also the qualities of storage sites (rate constants) declined after aging. The PGM and surface ceria interface (site S1) declined more severely compared to the sub-surface ceria (site S2). The change of the amount of oxygen storage sites as well as kinetics on the aged TWC sample are reported. From thermodynamic analysis, the alteration of the temperature dependence of OSC is attributed to the change of the thermodynamic properties of ceria. |
| Databáze: | OpenAIRE |
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