The influence of water and pH on adsorption and oxidation of CO on Pd/Al2O3—an investigation by attenuated total reflection infrared spectroscopy
| Autor: | Barbara Mojet, Sune Dalgaard Ebbesen, Leon Lefferts |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Inorganic chemistry
Analytical chemistry General Physics and Astronomy chemistry.chemical_element Infrared spectroscopy Metal chemistry.chemical_compound Adsorption chemistry Transition metal visual_art Attenuated total reflection visual_art.visual_art_medium Physical and Theoretical Chemistry Cobalt Palladium Carbon monoxide |
| Zdroj: | Phys. Chem. Chem. Phys.. 11:641-649 |
| ISSN: | 1463-9084 1463-9076 |
| Popis: | Adsorption and oxidation of carbon monoxide over a Pd/Al2O3 catalyst layer was investigated both in gas phase and water. Both adsorption and oxidation of CO are significantly affected by the presence of liquid water. Water influences the potential of the metal particles as well as the dipole moment of the adsorbed CO molecule directly, which is reflected both in large red shifts and a higher infrared intensity when experiments are carried out in water. Furthermore, the rate of CO oxidation increases significantly by both the presence of water and by increasing the pH. Enhancement of the oxidation rate is attributed to a weakening of the CO bond by increasing potential of the metal particle, similar to CO oxidation over Pt/Al2O3 as recently published [S. D. Ebbesen et al., J. Catal., 2007, 246, 66]. However, on Pd/Al2O3 the oxidation of palladium is clearly promoted at increasing pH, further enhancing the oxidation of CO over Pd/Al2O3. |
| Databáze: | OpenAIRE |
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