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Title: Surface reactions of ethanol over UO2(100) thin film

The study of the reactions of oxygenates on well-defined oxide surfaces is important for the fundamental understanding of heterogeneous chemical pathways that are influenced by atomic geometry, electronic structure, and chemical composition. In this work, an ordered uranium oxide thin film surface terminated in the (100) orientation is prepared on a LaAlO3 substrate and studied for its reactivity with a C-2 oxygenate, ethanol (CH3CH2OH). With the use of synchrotron X-ray photoelectron spectroscopy (XPS), we have probed the adsorption and desorption processes observed in the valence band, C 1s, O 1s, and U 4f to investigate the bonding mode, surface composition, electronic structure, and probable chemical changes to the stoichiometric-UO2(100) [smooth-UO2(100)] and Ar+-sputtered UO2(100) [rough-UO2(100)] surfaces. Unlike UO2(111) single crystal and UO2 thin film, Ar-ion-sputtering of this UO2(100) did not result in noticeable reduction of U cations. Upon ethanol adsorption (saturation occurred at 0.5 ML), only the ethoxy (CH3CH2O) species is formed on smooth-UO2(100) whereas initially formed ethoxy species are partially oxidized to surface acetate (CH3COO–) on the Ar+-sputtered UO2(100) surface. Furthermore, all ethoxy and acetate species are removed from the surface between 600 and 700 K.
Authors:
;  [1] ;  [2] ;  [1] ;  [3]
  1. Brookhaven National Lab. (BNL), Upton, NY (United States)
  2. Argonne National Lab. (ANL), Argonne, IL (United States)
  3. Centre for Research and Innovation (CRI) (Saudi Arabia)
Publication Date:
OSTI Identifier:
1235892
Report Number(s):
BNL--111755-2016-JA
Journal ID: ISSN 1932-7447; R&D Project: CO009; KC0302010
Grant/Contract Number:
SC00112704
Type:
Accepted Manuscript
Journal Name:
Journal of Physical Chemistry. C
Additional Journal Information:
Journal Volume: 119; Journal Issue: 44; Journal ID: ISSN 1932-7447
Publisher:
American Chemical Society
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