Role of Multivalent Pr in the Formation and Migration of Oxygen Vacancy in Pr-Doped Ceria: Experimental and First-Principles Investigations

Autor:	D. Hari Prasad, Hae-Weon Lee, Jong-Ho Lee, Dong Su Yoo, Kiyong Ahn, Yong-Chae Chung
Rok vydání:	2012
Předmět:	Extended X-ray absorption fine structure Chemistry General Chemical Engineering Coordination number Doping chemistry.chemical_element General Chemistry Oxygen Redox Ion Solid state ionics symbols.namesake Computational chemistry Materials Chemistry symbols Physical chemistry Raman spectroscopy
Zdroj:	Chemistry of Materials. 24:4261-4267
ISSN:	1520-5002 0897-4756
DOI:	10.1021/cm3022424
Popis:	We combined first-principles calculations with several experimental studies to investigate the complex role for high oxygen storage capacity (OSC) in multivalent Pr-doped ceria. TPR and Raman spectra were measured for confirming oxygen vacancy concentration and oxygen mobility. The coordination number was fitted via EXAFS spectra, and it was the correlated DFT calculation that has been corrected as effective U (5.3 eV) to well express the reducing state (4+ → 3+) for both Ce and Pr elements. In our study, when Pr is incorporated into pure ceria, Pr3+ and Pr4+ ions are incorporated as majority and minority ions, respectively. Pr3+ ions play a key role to create oxygen vacancies and induce a local distortion, which improves oxygen mobility, and Pr4+ can contribute to diminishing reduction energy and a respectable OSC via the formation of an additional redox couple.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::21ddd2dbc309e9f7a00062930ef0cbf4 https://doi.org/10.1021/cm3022424 Zobrazit plný text záznamu