Use of pyridine CH(D) vibrations for the study of Lewis acidity of metal oxides

Autor:	Arnaud Travert, Azziz Sahibed-Dine, Alexandre Vimont, Jean-Claude Lavalley, Marco Daturi
Rok vydání:	2006
Předmět:	chemistry.chemical_classification Infrared Process Chemistry and Technology Inorganic chemistry Infrared spectroscopy Protonation Catalysis Spectral line Metal Acid strength chemistry.chemical_compound chemistry visual_art Pyridine visual_art.visual_art_medium Physical chemistry
Zdroj:	Applied Catalysis A: General. 307:98-107
ISSN:	0926-860X
Popis:	C–H and C–D stretching vibrations of h 5 - and d 5 -pyridine adsorbed on various metal oxides have been investigated by infrared spectroscopy. Experimental spectra were further compared with density functional (DFT) calculations of the interaction of pyridine with cluster models. Both ν CH(D) frequencies and intensities are sensitive to the adsorption mode and allow one to distinguish between H-bonded, protonated and coordinated species. In the case of coordinated species, an increase in ν (CH) frequencies is observed and it could be correlated with the ν 8a and ν 19b frequency shifts which are commonly used to assess acid strength of metal oxides. It is found that the study of ν (CH) modes is more reliable than that of the ν 8a and ν 19b modes to distinguish H-bonded from weakly coordinated species. An example of such an application is given for the cases of CeO 2 , MgO and CaO.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::ed3ec055f222a937c948d97db6b84677 https://doi.org/10.1016/j.apcata.2006.03.011 Zobrazit plný text záznamu Full Text from ScienceDirect