In Situ Electrochemical X-ray Spectromicroscopy Investigation of the Reduction/Reoxidation Dynamics of Ni鈥揅u Solid Oxide Fuel Cell Anodic Material in Contact with a Cr Interconnect in 2 脳 10鈥?
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- 作者：Benedetto Bozzini ; Matteo Amati ; Luca Gregoratti ; Majid Kazemian ; Mauro Prasciolu ; Elisabetta Tondo ; Alexander L. Trygub ; Maya Kiskinova
- 刊名：The Journal of Physical Chemistry C
- 出版年：2012
- 出版时间：April 5, 2012
- 年：2012
- 卷：116
- 期：13
- 页码：7243-7248
- 全文大小：376K
- 年卷期：v.116,no.13(April 5, 2012)
- ISSN：1932-7455
文摘
Following our systematic investigations on the durability of solid oxide fuel cell (SOFC) components (Bozzini, B.; Tondo, E.; Prasciolu, M.; Amati, M.; Kazemian, M.; Gregoratti, L.; Kiskinova, M. ChemSusChem, http://dx.doi.org/10.1002/cssc.201100140), the present in situ scanning photoelectron microscopy study is focused on the redox behavior of Ni鈥揅u bilayers in contact with Cr, representing the anodic material and interconnects for SOFCs, respectively. The experiments with this model cell, using yttria-stabilized zirconia (YSZ) electrolyte, were carried out in 2 脳 10鈥? mbar O2 at 650 掳C at open circuit potential (OCP) and under applied potential. The elemental images and the spectra from selected parts of the cell have revealed dramatic compositional and morphological changes under OCP conditions, yielding Ni鈥揅u islands covered with NiO in the electrode region and a NiO network in the YSZ electrolyte region. The Ni reduction dynamics as a function of applied potential is followed by continuous monitoring of the evolution of the Ni 2p spectra in different regions, which allowed the location of electrochemically active areas of the half-cell upon cathodic polarization. It was shown that after electrochemical reduction the reoxidation at OCP results in notable morphology alterations of the triple-phase contact region, which can be related to the empirically observed degradation of catalytic performance.