BaCe1-xPdxO3- (0
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- 作者：Jun Li ; Udayshankar G. Singh ; Joseph W. Bennett ; Katharine Page ; James C. Weaver ; Jin-Ping Zhang ; Thomas Proffen ; Andrew M. Rappe ; Susannah Scott ; Ram Seshadri
- 刊名：Chemistry of Materials
- 出版年：2007
- 出版时间：March 20, 2007
- 年：2007
- 卷：19
- 期：6
- 页码：1418 - 1426
- 全文大小：814K
- 年卷期：v.19,no.6(March 20, 2007)
- ISSN：1520-5002
文摘
We demonstrate using a combination of X-ray and neutron diffraction and X-ray photoelectronspectroscopy that Pd2+ ions can be substituted for Ce in perovskite BaCeO3 and that, under oxidizingconditions, BaCe1-xPdxO3-
(0 
x 0.1) compositions can be prepared. Neutron diffraction has helpedverify that 
x, implying that Ce4+ ions are substituted by Pd2+ and that a vacancy is concurrentlycreated on the oxygen sublattice. The structure of the host compound and models for Pd substitutionhave also been studied using density functional theory, which has provided a detailed local descriptionof the structure. The Pd2+-containing perovskite phases extrude elemental face-centered cubic palladiumwhen heated in a reducing atmosphere. This elemental palladium is re-absorbed as ions into the perovskitelattice upon heating in flowing oxygen. Evidence for such cyclable ingress and egress of palladium underredox conditions is presented. A curious morphological change that results from the redox cycling ofBaCe1-xPdxO3- is the formation of perovskite nanowires, which we believe to arise from regrowth ofthe perovskite around particles of elemental palladium.
(0 x 0.1) compositions can be prepared. Neutron diffraction has helpedverify that x, implying that Ce4+ ions are substituted by Pd2+ and that a vacancy is concurrentlycreated on the oxygen sublattice. The structure of the host compound and models for Pd substitutionhave also been studied using density functional theory, which has provided a detailed local descriptionof the structure. The Pd2+-containing perovskite phases extrude elemental face-centered cubic palladiumwhen heated in a reducing atmosphere. This elemental palladium is re-absorbed as ions into the perovskitelattice upon heating in flowing oxygen. Evidence for such cyclable ingress and egress of palladium underredox conditions is presented. A curious morphological change that results from the redox cycling ofBaCe1-xPdxO3- is the formation of perovskite nanowires, which we believe to arise from regrowth ofthe perovskite around particles of elemental palladium.