Study of Hydrocarbon Adsorption on Oxide Catalysts by IR Spectroscopy. XX. Diffuse-Reflectance Spectra of Paraffins Adsorbed on Simple Oxides
Kinetics and Catalysis
, E-ISSN: 1608-3210
Boreskov Institute of Catalysis, Siberian Division, Russian Academy of Sciences, Novosibirsk, 630090 Russia
Analysis of diffuse-reflectance IR spectra of C-1 - C-6 paraffins adsorbed at 273 - 573 K on calcium, magnesium, zirconium, and aluminum oxides provides evidence for the formation of H-bonded hydrocarbon complexes on M(n+)O(2-) ionic pairs (M is a metal), which are characterized by a strong loosening of the C-H bond, and for the possibility of dissociative adsorption proceeding with the formation of metal-alkyl species. The probability of the latter process, occurring on a small part of the ionic pairs (the most defective sites) increases with increasing adsorption temperature.