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Structural and electronic properties of cubic CeO 2 : Unpaired electrons in CeO 2
Author(s) -
Quintanar Carlos,
Caballero Reyna,
Barreto Jorge,
Chavira Elizabeth,
Marinero Ernesto E.
Publication year - 2010
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.22874
Subject(s) - electron paramagnetic resonance , unpaired electron , vacancy defect , density functional theory , electron , chemistry , cluster (spacecraft) , cerium , cubic crystal system , materials science , condensed matter physics , crystallography , nuclear magnetic resonance , computational chemistry , physics , inorganic chemistry , computer science , quantum mechanics , programming language
The high performance of cerium dioxide (CeO 2 ) as support for Au in catalysis relies on its ability to anchor Au clusters and transfer charge to the gold nanoparticles. These two processes are governed by oxygen vacancy formation. To study the localization and the mobility of the electrons left behind by the vacancy from the relaxed oxygen, an experimental and theoretical study is hereby reported. CeO 2 powder was synthesized by the polyacrylamide gel method and its microstructure was characterized by X‐ray diffraction and high resolution scanning electron microscopy. We have determined the presence of only the fluorite cubic phase in our samples and the formation of acicular particles of ∼1 μm in length. In the electron spin resonance study, we observed that the unpaired electrons are quasi free. A single‐line paramagnetic signal is observed that exhibits spin characteristics with a g ‐value of 2.0039 at room temperature. This compares well to the value of 2.0023 determined for free electrons. In addition, we have conducted a theoretical study using a density functional theory cluster approach and calculate the electron spin density of CeO 2 clusters. We find that spin density clouds are localized around the cerium ions. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010