Near ambient pressure XPS investigation of the interaction of ethanol with Co/CeO2(1 1 1)

L. Óvári, S. Krick Calderon, Y. Lykhach, J. Libuda, A. Erdohelyi, C. Papp, J. Kiss, H. P. Steinrück

Research output: Contribution to journalArticle

68 Citations (Scopus)

Abstract

Near ambient pressure X-ray photoelectron spectroscopy was applied to study the interaction of ethanol (CH3CH2OH) with a well-ordered CeO2(1 1 1) film on Cu(1 1 1) and with a Co/CeO2(1 1 1)/Cu(1 1 1) model catalyst. The oxidation state of the surface and the chemical nature of reaction intermediates were analyzed. At 300 K, the oxidation state of ceria decreased gradually with increasing ethanol pressure. At a constant pressure of 0.1 mbar, the reduction of Ce4+ to Ce3+ increased significantly between 320 and 600 K due to a higher mobility of oxygen or Ce3+ centers at elevated temperatures. The main intermediate, ethoxide, was formed by dissociative adsorption of ethanol at room temperature. No coke formation was observed up to 600 K on CeO2. Upon deposition of metallic cobalt, partial reduction of ceria was observed, leading to the formation of Co2+ sites but still leaving metallic Co in the metal particles. During the reaction of ethanol with the Co/CeO2(1 1 1) model catalyst, the amount of Co2+ decreased drastically with increasing temperature, and at 600 K, the majority of Co was metallic. This process was accompanied by the severe reduction of ceria and the formation of significant carbon deposits.

Original languageEnglish
Pages (from-to)132-139
Number of pages8
JournalJournal of Catalysis
Volume307
DOIs
Publication statusPublished - Aug 27 2013

    Fingerprint

Keywords

  • Ceria
  • Cobalt
  • Ethanol steam reforming
  • Near ambient pressure
  • XPS

ASJC Scopus subject areas

  • Catalysis
  • Physical and Theoretical Chemistry

Cite this