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Adsorbed CO (adsorbed + co)

Distribution by Scientific Domains

Chemistry	100%

Selected Abstracts

Characterization of the Oxidation States of Supported Gold Species by IR Spectroscopy of Adsorbed CO

CHEMIE-INGENIEUR-TECHNIK (CIT), Issue 6 2007
M. Mihaylov Dr.
Abstract The use of IR spectroscopy of adsorbed CO for determination of gold speciation on supported gold catalysts is reviewed. Different ionic and metallic sites (Au3+, Au+, Au0, and Au,) can be differentiated on the basis of the frequency and stability of their surface carbonyl species formed after CO adsorption. In addition, the study of CO adsorption and reaction with other gases can provide unique information on the mechanisms of catalytic reactions with participation of CO. Finally, results from complementary techniques such as X-ray absorption spectroscopy, also useful for determination of gold oxidation state, are briefly considered. [source]

FTIR study of the CO adsorption over Pt/MFI catalysts: Ab initio interpretation

INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 10 2006
N. S. Nesterenko
Abstract The state and dispersion of Pt supported on MFI catalysts with different contents have been studied using Fourier transform infrared (FTIR) spectroscopy. Experimentally predicted Pt-containing complexes were simulated by density functional theory (DFT) for CO frequency shift estimation and determination of the relative intensities. According to DFT calculation and experimental data, a new interpretation was proposed. A new approach for estimation of the Pt dispersion based on IR spectra of adsorbed CO has been developed. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006 [source]

Support-dependent activity of noble metal substituted oxide catalysts for the water gas shift reaction

AICHE JOURNAL, Issue 10 2010
Parag A. Deshpande
Abstract The water gas shift reaction was carried out over noble metal ion substituted nanocrystalline oxide catalysts with different supports. Spectroscopic studies of the catalysts before and after the reaction showed different surface phenomena occurring over the catalysts. Reaction mechanisms were proposed based upon the surface processes and intermediates formed. The dual site mechanism utilizing the oxide ion vacancies for water dissociation and metal ions for CO adsorption was proposed to describe the kinetics of the reaction over the reducible oxides like CeO2. A mechanism based on the interaction of adsorbed CO and the hydroxyl group was proposed for the reaction over ZrO2. A hybrid mechanism based on oxide ion vacancies and surface hydroxyl groups was proposed for the reaction over TiO2. The deactivation of the catalysts was also found to be support dependent. Kinetic models for both activation and deactivation were proposed. © 2010 American Institute of Chemical Engineers AIChE J, 2010 [source]