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

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• 作者：Kiyong Ahn ; Dong Su Yoo ; D. Hari Prasad ; Hae-Weon Lee ; Yong-Chae Chung ; Jong-Ho Lee
• 刊名：Chemistry of Materials
• 出版年：2012
• 出版时间：November 13, 2012
• 年：2012
• 卷：24
• 期：21
• 页码：4261-4267
• 全文大小：450K
• 年卷期：v.24,no.21(November 13, 2012)
• ISSN：1520-5002

文摘

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+ 鈫?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.

Keywords:

hors" href="http://pubs.acs.org/action/doSearch?action=search&searchText=ceria&qsSearchArea=searchText">ceria; hors" href="http://pubs.acs.org/action/doSearch?action=search&searchText=density+functional+calculations&qsSearchArea=searchText">density functional calculations; hors" href="http://pubs.acs.org/action/doSearch?action=search&searchText=oxygen+storage+capacity&qsSearchArea=searchText">oxygen storage capacity; hors" href="http://pubs.acs.org/action/doSearch?action=search&searchText=solid%5C-state+ionics&qsSearchArea=searchText">solid-state ionics; hors" href="http://pubs.acs.org/action/doSearch?action=search&searchText=lattice+distortion&qsSearchArea=searchText">lattice distortion