In-situ IR spectroscopy as a probe of oxidation/reduction of Ce in nanostructured CeO2

Weiqiang Wu, Louisa Marie Savereide, Justin M Notestein, Eric Weitz

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

The redox properties of CeO2 are crucial in its applications in a wide range of catalytic processes. In the present research, in-situ IR spectroscopy is shown to be a viable and convenient method for the characterization of the oxidation state of Ce by monitoring the spin-orbit transition in Ce3+ (2F5/22F7/2) at ∼2147 cm−1. By monitoring this transition in CeO2 nanorods, the apparent activation energy for the production of oxygen vacancies that accompany the formation of Ce3+ has been determined and is shown to be lower for reduction with cyclohexene than with hydrogen. The bi-exponential kinetics for the formation of oxygen vacancies in CeO2 nanorods is discussed. An application of this method to real time monitoring of the oxidation state of Ce in the oxidation of cyclohexene on vanadia supported on ceria is presented as an example of how this method can be used as an operando probe of reaction mechanisms.

Original languageEnglish
Pages (from-to)548-554
Number of pages7
JournalApplied Surface Science
Volume445
DOIs
Publication statusPublished - Jul 1 2018

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Keywords

  • Ce
  • IR spectroscopy
  • Kinetics
  • Nanostructured CeO
  • Oxygen vacancies

ASJC Scopus subject areas

  • Surfaces, Coatings and Films

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