Study of two-step CO light-off kinetics on Pt/Al2O3, Pt/CeO2/Al2O3, Pd/Al2O3 and Pd/CeO2/Al2O3 automotive exhaust catalysts

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22340%2F19%3A43919763" target="_blank" >RIV/60461373:22340/19:43919763 - isvavai.cz</a>

Výsledek na webu

<a href="http://sschi.chtf.stuba.sk/ssche_conference2019.html" target="_blank" >http://sschi.chtf.stuba.sk/ssche_conference2019.html</a>

DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Study of two-step CO light-off kinetics on Pt/Al2O3, Pt/CeO2/Al2O3, Pd/Al2O3 and Pd/CeO2/Al2O3 automotive exhaust catalysts

Popis výsledku v původním jazyce

Social pressure on environmental quality leads to tightening of emission limits. For this reason, more efficient automotive exhaust gas after-treatment are constantly being developed. Significant emissions of pollutants occur during cold start, before the catalytic system is warmed up to its operating temperature. Two-step CO light-off is an undesired process during which CO conversion stagnates or decreases with increasing temperature depending on the inlet gas composition. This occurs only if CO is oxidized in the presence of hydrocarbons. Two mechanisms have been found that affect the CO oxidation. The first, more significant mechanism is a formation of hydrocarbon intermediates on the catalyst surface (ethylene, formaldehyde, formates and acetates). The intermediates are blocking the catalytically active centers and does not allow CO to be adsorbed and fully oxidized. The second mechanism is an incomplete hydrocarbon oxidation. To study and elucidate this phenomenon, series of experiments were designed and measured on four catalysts samples (Pt/Al2O3, Pd/Al2O3, Pt/CeO2/Al2O3 and Pd/CeO2/Al2O3,). The aim of this work was to obtain a detailed information on the kinetics of CO oxidation in the presence of other components, specifically C3H6, NO and O2, and to compare the performance of different catalyst formulations. A more significant two-step CO light-off effect occurs on both samples containing platinum. The samples containing CeO2 showed a better catalytic activity than the samples without ceria, but the extent of inhibition by the hydrocarbon intermediates was similar.

Název v anglickém jazyce

Study of two-step CO light-off kinetics on Pt/Al2O3, Pt/CeO2/Al2O3, Pd/Al2O3 and Pd/CeO2/Al2O3 automotive exhaust catalysts

Popis výsledku anglicky

Social pressure on environmental quality leads to tightening of emission limits. For this reason, more efficient automotive exhaust gas after-treatment are constantly being developed. Significant emissions of pollutants occur during cold start, before the catalytic system is warmed up to its operating temperature. Two-step CO light-off is an undesired process during which CO conversion stagnates or decreases with increasing temperature depending on the inlet gas composition. This occurs only if CO is oxidized in the presence of hydrocarbons. Two mechanisms have been found that affect the CO oxidation. The first, more significant mechanism is a formation of hydrocarbon intermediates on the catalyst surface (ethylene, formaldehyde, formates and acetates). The intermediates are blocking the catalytically active centers and does not allow CO to be adsorbed and fully oxidized. The second mechanism is an incomplete hydrocarbon oxidation. To study and elucidate this phenomenon, series of experiments were designed and measured on four catalysts samples (Pt/Al2O3, Pd/Al2O3, Pt/CeO2/Al2O3 and Pd/CeO2/Al2O3,). The aim of this work was to obtain a detailed information on the kinetics of CO oxidation in the presence of other components, specifically C3H6, NO and O2, and to compare the performance of different catalyst formulations. A more significant two-step CO light-off effect occurs on both samples containing platinum. The samples containing CeO2 showed a better catalytic activity than the samples without ceria, but the extent of inhibition by the hydrocarbon intermediates was similar.

Druh

D - Stať ve sborníku

CEP obor

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OECD FORD obor

20401 - Chemical engineering (plants, products)

Projekt

<a href="/cs/project/GA17-26018S" target="_blank" >GA17-26018S: Reakční kinetika v oxidačních katalyzátorech pro konverzi dieselových výfukových plynů za nízkých teplot</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2019

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

Proceedings 46th International Conference of the Slovak Society of Chemical Engineering

ISBN

978-80-8208-011-0

ISSN

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e-ISSN

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Počet stran výsledku

7

Strana od-do

1-7

Název nakladatele

Slovak Society of Chemical Engineering

Místo vydání

Bratislava

Místo konání akce

Tatranské Matliare

Datum konání akce

20. 5. 2019

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

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