Laboratory reactor system for three-way automotive catalyst evaluation

Schlatter, James C.; Sinkevitch, Robert M.; Mitchell, P. J.

doi:10.1021/i300009a013

Cited by 50 publications

(10 citation statements)

References 8 publications

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“…It has been shown that, at warmed-up converter temperatures, three-way catalysts can best accomplish the simultaneous removal of hydrocarbons, carbon monoxide, and nitric oxide when engine exhaust composition is maintained close to the stoichiometric point Schlatter et al, 1983;Taylor, 1984). Thus, steady operation at the stoichiometric point has been preferred to cyclic operation, and a faster frequency and/or smaller amplitude of composition cycling has been considered preferable.…”

Section: Introductionmentioning

confidence: 99%

Cyclic operation of platinum/alumina catalysts for carbon monoxide oxidation

Cho¹,

West²

1986

Ind. Eng. Chem. Fund.

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An experimental investigation of CO oxidation over well-characterized Pt/Al203 catalysts in an integral reactor under the conditions of forced feed composition cycling is presented, and various ways for possible improvements in the cyclic performance of automotive catalysts are considered. The effects of time-average feed composition, as well as of catalyst impregnation depth, on the cyclic performance are also examined. The results indicate that the most effective operating strategy for CO oxidation over Pt/Al203 catalysts is a hybrid scheme: cyclic operation during the warm-up period up to 300 °C and steady operation for temperatures above 300 °C. In the hightemperature range above 350 °C, the reaction yield for the stoichiometric cyclic operation may be improved by increasing the partial pressure of reactants. The chromatographic and antlchromatographic effects on the catalyst activity during cyclic operation are discussed.

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Section: Introductionmentioning

confidence: 99%

Cyclic operation of platinum/alumina catalysts for carbon monoxide oxidation

Cho¹,

West²

1986

Ind. Eng. Chem. Fund.

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“…Without real-time measurements of exhaust composition at the reactor inlet, we do not know exactly the extent of the gas-phase mixing as a function of cycling frequency. But from the previous studies (Sell et al, 1980;Schlatter et al, 1983), we know that at 1 Hz the amplitude of the concentration oscillation may not quite reach either end point due to attenuation by mixing. At 0.1 Hz, however, the amplitude should reach both end points.…”

Section: Description Of Experimentsmentioning

confidence: 83%

“…There are numerous reports in the reaction engineering literature that a catalyst's activity or selectivity can be enhanced under certain conditions by forced composition cycling (e.g., Billimoria and Bailey, 1978;Cutlip, 1979; Abdul-Kareem et al, 1980;Fiolitakis et al, 1983; Cho and West, 1986;Silveston et al, 1986). During warmed-up 0888-5885/88/2627-0030$01.50 / 0 operation of three-way catalytic converters, steady operation at the stoichiometrically balanced feed composition has been preferred to cyclic operation, and thus a high frequency and/or small amplitude of composition cycling is desirable (Schlatter et al, 1983;Taylor, 1984). Similar observations were reported by Cho and West (1986) for warmed-up CO oxidation activity over Pt/Al203.…”

mentioning

confidence: 99%

Performance of platinum/alumina catalysts in automobile engine exhaust with oscillatory air/fuel ratio

Cho¹

1988

Ind. Eng. Chem. Res.

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Kinetics of oxygen absorption in aqueous alkaline solutions of polyhydroxybenzenes (PHBs) such as pyrogallol (PG), p-ferf-butylcatechol (PTBC), íerf-butylhydroquinone (TBHQ), 2,3,5-trimethylhydroquinone (TMHQ), and gallic acid (GA) was studied in a jet apparatus, a stirred cell, and a model stirred contactor, at 29 ± 1 °C. In the cases of PTBC and TBHQ, the reaction was found to be first order in oxygen as well as PTBC or TBHQ. The intrinsic second-order rate constants were in the range of 1 X 103-1 X 105 n^/lkmohs). In the case of PG, GA, and TMHQ, the system conformed to the instantaneous reaction regime. The theory of gas absorption with an instantaneous reaction was used to calculate the diffusivity of dissolved PG and GA. At very low partial pressures of oxygen, the oxygen absorption in alkaline PG can become predominantly gas film controlled.

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“…Since the beginning of the previous decade, it has been recognized that the 3-way catalyst efficiency is significantly affected when the composition of the feed gas is modulated with different amplitudes and frequencies (Herz et al, 1983;Taylor and Sinkevitch, 1983;Schlatter et al, 1983). Since the beginning of the previous decade, it has been recognized that the 3-way catalyst efficiency is significantly affected when the composition of the feed gas is modulated with different amplitudes and frequencies (Herz et al, 1983;Taylor and Sinkevitch, 1983;Schlatter et al, 1983).…”

Section: Computation Of the Oxygen Storage And Release Phenomena In Tmentioning

confidence: 99%

Three-Way Catalytic Converter Modeling and Applications

Koltsakis

Kandylas

Stamatelos

1998

Chemical Engineering Communications

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Rsprinu availablr diroctlg lrom the publisher Photocopying permitted by liscnv only Q 1998 OPA (OMnsas Publinhen Audntian) Arnrtcrdam B. V. Published under liscnw under the Gordon and B m h Science Publirhm imprint. Prinvd in India.The advent of stricter US. and European exhaust emissions regulations has increased the need for reliable 3-way catalytic converter models supporting the design of demanding exhaust systems for low-emitting vehicles. Although a number of tunable models have been presented in the literature, their efficient performance in actual 3-way applicaions requires further development and validation. The major difficulties posed in such modeling eRorts arise from the complexities in the reaction schemes and the respective rate expressions for the multitude of currently used catalyst formulations. This paper addresses the details of tuning and real world application of a two-dimensional catalytic converter model, which accounts for the HC (hvdrocarbons) and CO oxidation. as well as NO reduction reactions. The model features a &mber of innbvations regarding the catalyst transient behaviour modelling and the reaction kinetics scheme. The advanced oxygen storage submodel presented is capable of accounting for the redox and temoerature deoendence of the oxveen availabilitv under transient ooeration. The ,redox sensitivity of the reaction scheme allows to get clearer insight in the "lambda-window" behavior of 3-way catalysts. It is concluded, that mathematical modelling may successfully describe important aspects of real world three-way catalytic converter operation under dynamic conditions, and thus, is a valid tool in exhaust aftertreatment systems optimization.

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Laboratory reactor system for three-way automotive catalyst evaluation

Cited by 50 publications

References 8 publications

Cyclic operation of platinum/alumina catalysts for carbon monoxide oxidation

Cyclic operation of platinum/alumina catalysts for carbon monoxide oxidation

Performance of platinum/alumina catalysts in automobile engine exhaust with oscillatory air/fuel ratio

Three-Way Catalytic Converter Modeling and Applications

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