Electron paramagnetic resonance spectra of CeO2catalyst for CO oxidation

✍ Scribed by C. Oliva; G. Termignone; F. P. Vatti; L. Forni; A. V. Vishniakov

• Publisher: Springer
• Year: 1996
• Tongue: English
• Weight: 543 KB
• Volume: 31
• Category: Article
• ISSN: 0022-2461
• DOI: 10.1007/bf00354457

✦ Synopsis

The EPR spectra of freshly prepared CeO2 samples as well as of samples used as a catalyst in the oxidation of CO to CO2 are reported. Attribution of these patterns to oxygen species O~-, O2, O-, or to Ce 3+ ions is discussed and dynamic phenomena involving these species are described. Bottlenecked systems between conduction electrons and Ce 3 § ions are envoked to explain the observation of the Ce 3+ EPR spectrum up to temperatures of about 370 K. Oxygen-deficient systems are obtained when the sample is used as a catalyst for CO oxidation in the presence of pyrex or quartz powder as a diluent, showing that the latter can play some role in stabilizing such species.