The kinetics of n-hexane and toluene complete oxidation has been studied over 0.12% Pt/Al 2 O 3 catalysts. Measurements were performed in an external recycle reactor. Reaction rates were measured as a function of temperature and reactants concentrations for two platinum crystallite sizes, 1.0 and 15.5 nm. The turnover frequency (TOF) for the oxidation of both hydrocarbons is about 10 times higher for the 15.5 nm than for the 1.0 nm Pt crystallite size. The reaction constants are calculated according to Mars van Krevelen (MVK) mechanism. The oxygen chemisorption rate constant (k O ) is the same during the n-hexane and the toluene oxidation for each sizes of platinum crystallite. For both hydrocarbons the oxygen chemisorption rate constant and the surface reaction rate constant (k i ) are higher for 15.5 nm than for 1.0 nm crystallite size. The activation energy for k O decreases with the increase of the Pt crystallite size. The activation energy for k i is independent on the Pt crystall...ite size for both hydrocarbons. The values of kinetic constants reveal that the increase of the reaction rate for large Pt crystallites could be related to the lower activation energy for k O . This implies that on large Pt crystallites oxygen is held on Pt atoms with a lower bond strength that on small Pt crystallites, which explains the structure sensitivity found for n-hexane and toluene oxidation.
TY - JOUR
AU - Radić, Nenad
AU - Grbić, Boško
AU - Terlecki-Baričević, Ana V.
PY - 2004
UR - https://cer.ihtm.bg.ac.rs/handle/123456789/4118
AB - The kinetics of n-hexane and toluene complete oxidation has been studied over 0.12% Pt/Al 2 O 3 catalysts. Measurements were performed in an external recycle reactor. Reaction rates were measured as a function of temperature and reactants concentrations for two platinum crystallite sizes, 1.0 and 15.5 nm. The turnover frequency (TOF) for the oxidation of both hydrocarbons is about 10 times higher for the 15.5 nm than for the 1.0 nm Pt crystallite size. The reaction constants are calculated according to Mars van Krevelen (MVK) mechanism. The oxygen chemisorption rate constant (k O ) is the same during the n-hexane and the toluene oxidation for each sizes of platinum crystallite. For both hydrocarbons the oxygen chemisorption rate constant and the surface reaction rate constant (k i ) are higher for 15.5 nm than for 1.0 nm crystallite size. The activation energy for k O decreases with the increase of the Pt crystallite size. The activation energy for k i is independent on the Pt crystallite size for both hydrocarbons. The values of kinetic constants reveal that the increase of the reaction rate for large Pt crystallites could be related to the lower activation energy for k O . This implies that on large Pt crystallites oxygen is held on Pt atoms with a lower bond strength that on small Pt crystallites, which explains the structure sensitivity found for n-hexane and toluene oxidation.
PB - Elsevier
T2 - Applied Catalysis B: Environmental
T1 - Kinetics of deep oxidation of n-hexane and toluene over Pt/Al2O3 catalysts: Platinum crystallite size effect
VL - 50
IS - 3
SP - 153
EP - 159
DO - 10.1016/j.apcatb.2004.01.011
ER -
@article{
author = "Radić, Nenad and Grbić, Boško and Terlecki-Baričević, Ana V.",
year = "2004",
url = "https://cer.ihtm.bg.ac.rs/handle/123456789/4118",
abstract = "The kinetics of n-hexane and toluene complete oxidation has been studied over 0.12% Pt/Al 2 O 3 catalysts. Measurements were performed in an external recycle reactor. Reaction rates were measured as a function of temperature and reactants concentrations for two platinum crystallite sizes, 1.0 and 15.5 nm. The turnover frequency (TOF) for the oxidation of both hydrocarbons is about 10 times higher for the 15.5 nm than for the 1.0 nm Pt crystallite size. The reaction constants are calculated according to Mars van Krevelen (MVK) mechanism. The oxygen chemisorption rate constant (k O ) is the same during the n-hexane and the toluene oxidation for each sizes of platinum crystallite. For both hydrocarbons the oxygen chemisorption rate constant and the surface reaction rate constant (k i ) are higher for 15.5 nm than for 1.0 nm crystallite size. The activation energy for k O decreases with the increase of the Pt crystallite size. The activation energy for k i is independent on the Pt crystallite size for both hydrocarbons. The values of kinetic constants reveal that the increase of the reaction rate for large Pt crystallites could be related to the lower activation energy for k O . This implies that on large Pt crystallites oxygen is held on Pt atoms with a lower bond strength that on small Pt crystallites, which explains the structure sensitivity found for n-hexane and toluene oxidation.",
publisher = "Elsevier",
journal = "Applied Catalysis B: Environmental",
title = "Kinetics of deep oxidation of n-hexane and toluene over Pt/Al2O3 catalysts: Platinum crystallite size effect",
volume = "50",
number = "3",
pages = "153-159",
doi = "10.1016/j.apcatb.2004.01.011"
}
Radić, N., Grbić, B.,& Terlecki-Baričević, A. V. (2004). Kinetics of deep oxidation of n-hexane and toluene over Pt/Al2O3 catalysts: Platinum crystallite size effect.
Applied Catalysis B: Environmental
Elsevier., 50(3), 153-159.
https://doi.org/10.1016/j.apcatb.2004.01.011
Radić N, Grbić B, Terlecki-Baričević AV. Kinetics of deep oxidation of n-hexane and toluene over Pt/Al2O3 catalysts: Platinum crystallite size effect. Applied Catalysis B: Environmental. 2004;50(3):153-159
Radić Nenad, Grbić Boško, Terlecki-Baričević Ana V., "Kinetics of deep oxidation of n-hexane and toluene over Pt/Al2O3 catalysts: Platinum crystallite size effect" Applied Catalysis B: Environmental, 50, no. 3 (2004):153-159,
https://doi.org/10.1016/j.apcatb.2004.01.011 .
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