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Influence of Vanadium or Cobalt Oxides on the CO Oxidation Behavior of Au/MO x /CeO 2 –Al 2 O 3 Systems
Author(s) -
Reina Tomás Ramírez,
Moreno Andrea Álvarez,
Ivanova Svetlana,
Odriozola José Antonio,
Centeno Miguel Angel
Publication year - 2012
Publication title -
chemcatchem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.497
H-Index - 106
eISSN - 1867-3899
pISSN - 1867-3880
DOI - 10.1002/cctc.201100373
Subject(s) - catalysis , cobalt , cerium oxide , vanadium , cerium , redox , inorganic chemistry , materials science , cobalt oxide , raman spectroscopy , stoichiometry , vanadium oxide , oxide , chemistry , metallurgy , physics , optics , biochemistry
A series of V 2 O 5 ‐ and Co 3 O 4 ‐modified ceria/alumina supports and their corresponding gold catalysts were synthesized and their catalytic activities evaluated in the CO oxidation reaction. V 2 O 5 ‐doped solids demonstrated a poor capacity to abate CO, even lower than that of the original ceria/alumina support, owing to the formation of CeVO 4 . XRD, Raman spectroscopy, and H 2 ‐temperature programmed reduction studies confirmed the presence of this stoichiometric compound, in which cerium was present as Ce 3+ and its redox properties were avoided. Co 3 O 4 ‐doped supports showed a high activity in CO oxidation at subambient temperatures. The vanadium oxide‐doped gold catalysts were not efficient because of gold particle agglomeration and CeVO 4 formation. However, the gold–cobalt oxide–ceria/alumina catalysts demonstrated a high capacity to abate CO at and below room temperature. Total conversion was achieved at −70 °C. The calculated apparent activation energy values revealed a theoretical optimum loading of a half‐monolayer.