Structure sensitivity of selective CO oxidation over Pt/gamma-Al2O3

Atalik, B.
Üner, Deniz
In this study, the effect of particle size on the reaction rate and selectivity of preferential oxidation of CO (PROX) reaction was investigated on 2 wt% Pt/-Al2O3 catalysts prepared by an incipient wetness technique. The particle size of the catalysts was modified by calcination temperature and duration. CO oxidation and preferential CO oxidation reaction were studied on these catalysts at lambda = 2 (P-O2/P-CO) = 1. The CO oxidation reaction activation energy decreased with increasing particle size, consistent with previous reports. CO reaction orders exhibited no systematic change with respect to particle size, but a minor but systematic decrease in the CO oxidation reaction order was seen with respect to oxygen partial pressure with decreasing particle size, indicating higher selectivity toward PROX reactions at higher; on larger particles. On catalysts with 69 and 83% dispersions, the light-off curves were identical in hydrogen-free streams, whereas on the catalyst with higher dispersion, the light-off temperature was lower in the presence of hydrogen, indicating that the hydrogen oxidation reaction was more facile on catalysts with more defect sites. (c) 2006 Elsevier Inc. All rights reserved.


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Savargaonkar, N; Narayan, RL; Pruski, M; Üner, Deniz; King, TS (Elsevier BV, 1998-08-15)
The dynamics and energetics of hydrogen chemisorption on silica-supported ruthenium and ruthenium-silver bimetallic catalysts were studied by H-1 NMR spectroscopy and microcalorimetry. It was observed that the amount of hydrogen adsorbed on Ru particles having intermediate and low heats of adsorption was significantly reduced with increasing amounts of silver. The desorption and adsorption rate constants, determined from selective excitation NMR experiments, were lower on Ru-Ag catalysts than those on Ru ca...
Üner, Deniz; GERSTEIN, BC; KING, TS (Elsevier BV, 1994-04-01)
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OZKAN, UMIT; KUMTHEKAR, MAHESH; Karakaş, Gürkan (Elsevier BV, 1997-10-01)
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Liquid chromatography as a novel method for determination of the dispersion of supported Fd particles
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A solution-based method has been developed for determination of the number of active centers on Pd particles responsible for alkene hydrogenation in the liquid phase. Pd/gamma-Al2O3 was placed in a liquid chromatographic (LC) column, and the CS2 uptake of the catalyst was determined by applying CS2 pulses in methanol solution until surface saturation was attained. The reliability of the LC method was confirmed by quantitative CS2 poisoning of the catalyst in the liquid-phase hydrogenation of styrene to ethy...
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Citation Formats
B. Atalik and D. Üner, “Structure sensitivity of selective CO oxidation over Pt/gamma-Al2O3,” JOURNAL OF CATALYSIS, pp. 268–275, 2006, Accessed: 00, 2020. [Online]. Available: