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Title: Active Gold-Ceria and Gold-Ceria/titania Catalysts for CO Oxidation. From Single-Crystal Model Catalysts to Powder Catalysts

We studied CO oxidation on model and powder catalysts of Au-CeO2 and Au-CeOx/TiO2. Phenomena observed in Au-CeO2(1 1 1) and Au-CeO2/TiO2(1 1 0) provided useful concepts for designing and preparing highly active and stable Au-CeOx/TiO2 powder catalysts for CO oxidation. Small particles of Au dispersed on CeO2(1 1 1) displayed high catalytic activity, making Au-CeO2(1 1 1) a better CO oxidation catalyst than Au-TiO2(1 1 0) or Au-MgO(1 0 0). An excellent support for gold was found after depositing nanoparticles of ceria on TiO2(1 1 0). The CeOx nanoparticles act as nucleation centers for gold, improving dispersion of the supported metal and helping in the creation of reaction sites efficient for the adsorption of CO and the dissociation of the O2 molecule. High-surface area catalysts were prepared by depositing gold on ceria nanorods and CeOx/TiO2 powders. The samples were tested for the low-temperature (10–70 °C) oxygen-rich (1%CO/4%O2/He) CO oxidation reaction after pre-oxidation (20%O2/He, 300 °C) and pre-reduction (5%H2/He, 300 °C) treatments. Moreover, synchrotron-based operando X-ray diffraction (XRD) and X-ray absorption (XAS) spectroscopy were used to study the Au-CeO2 and Au-CeOx/TiO2 catalysts under reaction conditions. Our operando findings indicate that the most active phase of these catalysts for low-temperature CO oxidationmore » consist of small particles of metallic Au dispersed on CeO2 or CeOx/TiO2.« less
Authors:
 [1] ;  [1] ;  [2] ;  [1] ;  [1] ;  [1] ;  [1]
  1. Brookhaven National Lab. (BNL), Upton, NY (United States)
  2. Central Univ. of Venezuela, Caracas (Venezuela)
Publication Date:
OSTI Identifier:
1228903
Report Number(s):
BNL--110978-2015-JA
Journal ID: ISSN 0920-5861
DOE Contract Number:
SC00112704
Resource Type:
Journal Article
Resource Relation:
Journal Name: Catalysis Today; Journal Volume: 240
Publisher:
Elsevier
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY