Open AccessRedox-mediated C–C bond scission in alcohols adsorbed on CeO2− x thin films
Author(s) -
Yaroslava Lykhach,
Viktor Johánek,
Armin Neitzel,
Tomáš Škála,
Nataliya Tsud,
Klára Beranová,
Josef Mysliveček,
Olaf Brummel,
Jörg Libuda
Publication year - 2022
Publication title -
journal of physics. condensed matter
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.908
H-Index - 228
eISSN - 1361-648X
pISSN - 0953-8984
DOI - 10.1088/1361-648x/ac5138
Subject(s) - bond cleavage , ethylenedioxy , chemistry , alkoxy group , stoichiometry , desorption , acetaldehyde , x ray photoelectron spectroscopy , crystallography , photochemistry , adsorption , ethanol , organic chemistry , catalysis , chemical engineering , alkyl , engineering
The decomposition mechanisms of ethanol and ethylene glycol on well-ordered stoichiometric CeO 2 (111) and partially reduced CeO 2− x (111) films were investigated by means of synchrotron radiation photoelectron spectroscopy, resonant photoemission spectroscopy, and temperature programmed desorption. Both alcohols partially deprotonate upon adsorption at 150 K and subsequent annealing yielding stable ethoxy and ethylenedioxy species. The C–C bond scission in both ethoxy and ethylenedioxy species on stoichiometric CeO 2 (111) involves formation of acetaldehyde-like intermediates and yields CO and CO 2 accompanied by desorption of acetaldehyde, H 2 O, and H 2 . This decomposition pathway leads to the formation of oxygen vacancies. In the presence of oxygen vacancies, C–O bond scission in ethoxy species yields C 2 H 4 . In contrast, C–C bond scission in ethylenedioxy species on the partially reduced CeO 2− x (111) is favored with respect to C–O bond scission and yields methanol, formaldehyde, and CO accompanied by the desorption of H 2 O and H 2 . Still, scission of C–O bonds on both sides of the ethylenedioxy species yields minor amounts of accompanying C 2 H 4 and C 2 H 2 . C–O bond scission is coupled with a partial recovery of the lattice oxygen in competition with its removal in the form of water.