TY - JOUR
T1 - Acetylene and carbon monoxide oxidation over a Pt/Rh/CeO2/γ-Al2O3 automotive exhaust gas catalyst: kinetic modelling of transient experiments
AU - Harmsen, J.M.A.
AU - Hoebink, J.H.B.J.
AU - Schouten, J.C.
PY - 2001
Y1 - 2001
N2 - The transient kinetics of acetylene (C2H2) conversion by oxygen over a commercial Pt/Rh/CeO2/¿-Al2O3 three-way catalyst have been modelled. Experiments to validate the model were carried out in a fixed-bed reactor with two separate inlets, enabling alternate feeding of acetylene and oxygen. Frequencies of feed composition cycling up to 1/6 Hz were applied. The experimental conditions resemble the cold-start period of an Otto engine. Two types of adsorbed acetylene species seem to exist. A selective catalyst deactivation for oxygen adsorption, due to deposition of carbonaceous deposits, was found. Ceria proved to have a significant influence on the acetylene oxidation. A kinetic model was developed for the conversion of acetylene to carbon monoxide, based on elementary reaction steps. This model was combined with the published kinetics for transient carbon monoxide oxidation to carbon dioxide over the same catalyst (Nibbelke, R. H., Chapman, M. A. J., Hoebink, J. H. B. J., & Marin, G. B. (1997). Kinetic study of the CO oxidation over Pt/V-Al2O3 and Pt/Rh/ CeO2/¿-Al2O3 in the presence of H2O and CO2. Journal of Catalysis, 171, 358–373.), in order to describe the total oxidation of acetylene quantitatively. The combined model is able to describe the results of the transient experiments on simultaneous acetylene and carbon monoxide oxidation. During a transient, both acetylene and carbon monoxide react mainly in a front moving through the reactor, carbon monoxide hardly influencing the acetylene oxidation.
AB - The transient kinetics of acetylene (C2H2) conversion by oxygen over a commercial Pt/Rh/CeO2/¿-Al2O3 three-way catalyst have been modelled. Experiments to validate the model were carried out in a fixed-bed reactor with two separate inlets, enabling alternate feeding of acetylene and oxygen. Frequencies of feed composition cycling up to 1/6 Hz were applied. The experimental conditions resemble the cold-start period of an Otto engine. Two types of adsorbed acetylene species seem to exist. A selective catalyst deactivation for oxygen adsorption, due to deposition of carbonaceous deposits, was found. Ceria proved to have a significant influence on the acetylene oxidation. A kinetic model was developed for the conversion of acetylene to carbon monoxide, based on elementary reaction steps. This model was combined with the published kinetics for transient carbon monoxide oxidation to carbon dioxide over the same catalyst (Nibbelke, R. H., Chapman, M. A. J., Hoebink, J. H. B. J., & Marin, G. B. (1997). Kinetic study of the CO oxidation over Pt/V-Al2O3 and Pt/Rh/ CeO2/¿-Al2O3 in the presence of H2O and CO2. Journal of Catalysis, 171, 358–373.), in order to describe the total oxidation of acetylene quantitatively. The combined model is able to describe the results of the transient experiments on simultaneous acetylene and carbon monoxide oxidation. During a transient, both acetylene and carbon monoxide react mainly in a front moving through the reactor, carbon monoxide hardly influencing the acetylene oxidation.
U2 - 10.1016/S0009-2509(00)00498-X
DO - 10.1016/S0009-2509(00)00498-X
M3 - Article
SN - 0009-2509
VL - 56
SP - 2019
EP - 2035
JO - Chemical Engineering Science
JF - Chemical Engineering Science
IS - 6
ER -