Interfacial Charge Transfer and Chemical Bonding in a Ni鈥揕aNbO4 Cermet for Proton-Conducting Solid-Oxide Fuel Cell Anodes

详细信息    查看全文

• 作者：Despoina-Maria Kepaptsoglou ; Kianoosh Hadidi ; Ole-Martin L酶vvik ; Anna Magraso ; Truls Norby ; Anette E. Gunn忙s ; Arne Olsen ; Quentin M. Ramasse
• 刊名：Chemistry of Materials
• 出版年：2012
• 出版时间：November 13, 2012
• 年：2012
• 卷：24
• 期：21
• 页码：4152-4159
• 全文大小：585K
• 年卷期：v.24,no.21(November 13, 2012)
• ISSN：1520-5002

文摘

In this work, we present an atomic scale study of the structural and chemical characteristics of interfaces between Ni and LaNbO₄ grains in Ni鈥揕aNbO₄ cermets, a model composite material for anodes in proton-conducting solid-oxide fuel cells (SOFC). Electron energy loss spectroscopy (EELS) performed in an aberration-corrected scanning transmission electron microscope reveals the absence of reaction or interdiffusion layers at the interface. Changes in the valence state of Ni as well as in the electronic structure of La, reflected by changes in the EELS fine features at the interface, are shown to be related to charge transfer across the interface. The experimental results are in excellent agreement with ab initio calculations based on density functional theory, which predict that direct chemical bonds are formed between the metal and the ceramic at this abrupt interface, resulting in a redistribution of electronic charge across the interface.

Keywords:

g/action/doSearch?action=search&searchText=scanning+transmission+electron+microscopy&qsSearchArea=searchText">scanning transmission electron microscopy; g/action/doSearch?action=search&searchText=electron+energy+loss+spectroscopy&qsSearchArea=searchText">electron energy loss spectroscopy; g/action/doSearch?action=search&searchText=density+functional+theory&qsSearchArea=searchText">density functional theory; g/action/doSearch?action=search&searchText=charge+transfer&qsSearchArea=searchText">charge transfer; g/action/doSearch?action=search&searchText=proton%5C-conducting+solid+oxide+fuel+cells&qsSearchArea=searchText">proton-conducting solid oxide fuel cells; g/action/doSearch?action=search&searchText=electrodes&qsSearchArea=searchText">electrodes; g/action/doSearch?action=search&searchText=metal%2Foxide+interfaces&qsSearchArea=searchText">metal/oxide interfaces; g/action/doSearch?action=search&searchText=LaNbO4&qsSearchArea=searchText">LaNbO₄