CO Oxidation over Mono and Bi-Metallic Sequentially Impregnated Pd-Pt Catalysts

2008-01-01
Kaya, Sarp
Üner, Deniz
The CO oxidation capability of sequentially impregnated Pd-Pt/gamma-Al(2)O(3) bimetallic catalysts was tested. The CO oxidation light-off curves were hierarchically spaced between monometallic Pd and monometallic Pt, which showed the highest and lowest activity, respectively, indicating that sequential impregnation did not result in the formation of bimetallic particles, but that the catalysts remained as monometallic entities over the support surface. An investigation of the effect of CO partial pressure on the reaction rates over monometallic catalysts indicated that in the presence of excess CO the surface of Pt was poisoned. On the other hand, in the presence of excess CO the reaction rates over Pd catalysts remained constant due to the availability of the subsurface oxygen pools in PdO layers.
TURKISH JOURNAL OF CHEMISTRY

Suggestions

On the Structure Sensitivity of CO Oxidation on Alumina Supported Pd-Pt Bimetallic Catalysts
Kaya, Sarp; Erunal, Ebru; Shaltaf, Riad; Ellialtıoğlu, Süleyman Şinasi; Üner, Deniz (2009-01-01)
CO oxidation reaction was studied over monometallic and bimetallic palladium-platinum catalysts at 25:75, 50:50, and 75:25 Pd:Pt atomic fractions co-impregnated over a gamma-Al2O3 support. The size of the metal particles, measured by modified hydrogen chemisorption, increased as the Pd fractions in the catalyst increased. The surface compositions and site metal distributions of the catalysts determined from Monte Carlo simulations indicated that Pd atoms segregated to the surface: at low Pd levels, Pd occup...
Partial oxidation of methane on the SiO2 surface - A quantum chemical study
Ozturk, S; Onal, I; Senkan, S (2000-02-01)
Reaction pathways for methane partial oxidation (MPO) on silica were theoretically investigated using the semiempirical MOPAC-PM3 molecular orbital method. The surface of SiO2 was modeled by a helical Si6O18H12 molecular cluster that also exhibits a strained siloxane bridge defect. First, a bond energy analysis was performed on the silica cluster with isolated 3- and 4-coordinated Si surface atoms. Calculated bond dissociation energies for Si-H, SiO-H, and SI-OH were comparable to H-CH3, H-OH, and O-O. In t...
Thermal stability and SO2 resistance of Pd/Rh-perovskite based three-way catalyst wash-coated on cordierite monoliths
Bayram, Bilal; Önal, Işık; Külah, Görkem (2022-01-01)
The effect of hydrothermal aging and SO2 poisoning on the three-way catalytic performance of dispersed Pd/Rh-based and Pd/Rh perovskite-based catalysts were studied by using a dynamic activity test system that simulates redox fluctuations of gasoline engine exhaust conditions. Both catalysts were supported on ceria-zirconia-alumina and wash-coated on cordierite monoliths and were characterized by ICP-OES, BET, XRD, TEM-EDX, DRIFTS, and CO chemisorption. Their performance was very close when the catalysts we...
Electrochemical and chemical oxidation of K(C2H5OCS2),[Ni(C2H5OCS2)(2)] and [N(C2H5)(4)][Ni(C2H5OCS2)(3)]
Dag, O; Önal, Ahmet Muhtar; Isci, H (1996-06-26)
Electrochemical and chemical oxidation of (Et-Xan(-)), [Ni(Et-Xan)(2)] and [Ni(Et-Xan)(3)](-) (Et-Xan(-) = C2H5OCS2- have been studied by Cyclic Voltammetry and in situ UV-Vis spectroscopy in acetonitrile at room temperature. Cyclic Voltammograms (CV) of Et-Xan(-) and Ni(Et-Xan)(2) display one (0.00 V) and two (0.35 and 0.80 V) irreversible oxidation peaks, respectively, referenced to Ag/Ag+(0.10 M) electrode. However, CV of Ni(Et-Xan)(3)(-) displays one reversible (-0.15 V) and two irreversible (0.35, 0.80...
Poly(n-vinyl-2-pyrrolidone) stabilized nickel(0) nanoparticles as catalyst for hydrogen generation from the methanolysis of ammonia borane
Kılıçaslan, Nihan Zülay; Özkar, Salim; Department of Chemistry (2015)
This dissertion includes the preparation and characterization of poly(N-vinyl-2-pyrrolidone) stabilized nickel(0) nanoparticles, and investigation of their catalytic activity in hydrogen generation from catalytic methanolysis of ammonia-borane (AB). PVP-stabilized nickel(0) nanoparticles were prepared from the reduction of nickel(II) ethylhexanoate in the presence of PVP as stabilizer, by hydrazine borane at room temperature. PVP-stabilized nickel(0) nanoparticles were isolated from reaction medium by centr...
Citation Formats
S. Kaya and D. Üner, “CO Oxidation over Mono and Bi-Metallic Sequentially Impregnated Pd-Pt Catalysts,” TURKISH JOURNAL OF CHEMISTRY, pp. 645–652, 2008, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/54284.