Nitric oxide (NO) is a major pollutant which is produced by the combustion of fossil fuels. Current three-way catalyst (TWC) technology, used for the reduction of NO in automobile exhaust, is effective only under stoichiometric or net reducing conditions which cause incomplete use of the fuel and CO and hydrocarbon pollution. Excessively-exchanged Cu-ZSM-5 zeolite was investigated as a catalyst for the reduction of NO in net oxidizing exhaust mixtures, which would allow for greater fuel efficiency and lower NO, CO and hydrocarbon emissions. / Cu-ZSM-5 powder was pelletized by extrusion and the activity for the reduction of NO by CO on the presence of O$ sb2$ was measured at temperatures of 200$ sp circ$C to 550$ sp circ$C and a space velocity of 450 hour$ sp{-1}.$ The activity of the Cu-ZSM-5 was compared to that of a TWC at 550$ sp circ$C. Under stoichiometric or net reducing conditions the conversion to N$ sb2$ over both catalysts was about 100%. Under net oxidizing conditions (when the equivalence ratio, $ lambda$, is greater than 1) the conversion decreased with increasing oxygen concentration for both catalysts, but the Cu-ZSM-5 was much more active; at $ lambda=1.3$ the conversion was 53% compared to 26%. The Cu-ZSM-5 was found to deactivate after 30 hours of use. The deactivation was accompanied by a change in the Cu-ZSM-5 structure, and a change in the chemical composition. The deactivation was not found to be a function of the composition, or of the oxidative nature of the conditioning gas used (20% O$ sb2,$ inert, or 20% CO). Regeneration of the Cu-ZSM-5 proved unsuccessful.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.26388 |
| Date | January 1994 |
| Creators | Gilchrist, Ian Thomas |
| Contributors | Berk, D. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Engineering (Department of Chemical Engineering.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001433820, proquestno: MM99964, Theses scanned by UMI/ProQuest. |
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