ISSN:
1572-9028
Keywords:
CO adsorption
;
CO reaction
;
vanadium oxide–Pd(111) catalyst
;
catalyst surface
;
HREELS
;
XPS
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract The room temperature adsorption and reaction of CO on Pd(111) surfaces decorated with submonolayer coverages of vanadium oxide – so-called “inverse” model catalysts – have been studied by high-resolution electron energy loss spectroscopy (HREELS) and X-ray photoelectron spectroscopy (XPS). The HREELS surface phonon spectra of the V oxide phases have been measured and used to monitor the changes in the oxide as a result of the interaction with CO. The intramolecular C–O stretching frequency of CO adsorbed on the V-oxide/Pd(111) surfaces displays two vibrational loss components as a function of CO coverage as it has been observed on the clean Pd(111) surface. The relative intensities of the two vibrational features as a function of V oxide coverage however suggest that the balance of CO adsorption sites is modified as compared to clean Pd(111) by the presence of the V oxide–Pd phase boundary. Preferential population of high coordination adsorption sites by CO in the vicinity of the oxide–metal interface is proposed. The analysis of the V oxide phonon spectra indicates that adsorbed CO partially reduces the V oxide at the boundaries of the oxide islands to the Pd metal. The reduction of V oxide by CO is dependent on the oxygen content of the V oxide phase. The reduction of V oxide is confirmed by the XPS V 2p core level shifts.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1009046730688
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