title: Electrochemically Driven Deactivation and Recovery in PrBaCo2 O5+δ Oxygen Electrodes for Reversible Solid Oxide Fuel Cells.
abstract: The understanding of surface chemistry changes on oxygen electrodes is critical for the development of reversible solid oxide fuel cell (RSOFC). Here, we report for the first time that the electrochemical potentials can drastically affect the surface composition and hence the electrochemical activity and stability of PrBaCo2 O5+δ (PBCO) electrodes. Anodic polarization degrades the activity of the PBCO electrode, whereas the cathodic bias could recover its performance. Alternating anodic/cathodic polarization for 180 h confirms this behavior. Microstructure and chemical analysis clearly show that anodic bias leads to the accumulation and segregation of insulating nanosized BaO on the electrode surface, whereas cathodic polarization depletes the surface species. Therefore, a mechanism based on the segregation and incorporation of BaO species under electrochemical potentials is considered to be responsible for the observed deactivation and recovery process, respectively.
authors: Department of Physics, Harbin Institute of Technology, 92 West Dazhi Str., Harbin, Heilongjiang, 150001, P.R. China.
authors: Lin
authors: L
authors: Zhu
authors: Department of Physics, Harbin Institute of Technology, 92 West Dazhi Str., Harbin, Heilongjiang, 150001, P.R. China. bowei@hit.edu.cn.
authors: Bo
authors: 0000-0002-3755-6542
authors: B
authors: Wei
authors: Department of Physics, Harbin Institute of Technology, 92 West Dazhi Str., Harbin, Heilongjiang, 150001, P.R. China.
authors: Zhihong
authors: Z
authors: Wang
authors: Fuels and Energy Technology Institute, Curtin University, 1 Turner Avenue, Perth, WA, 6102, Australia.
authors: Kongfa
authors: K
authors: Chen
authors: Institute of Physical Chemistry, RWTH Aachen University, 2 Landoltweg, 52056, Aachen, Germany.
authors: Haiwu
authors: H
authors: Zhang
authors: Department of Physics, Harbin Institute of Technology, 92 West Dazhi Str., Harbin, Heilongjiang, 150001, P.R. China.
authors: Yaohui
authors: Y
authors: Zhang
authors: Department of Physics, Harbin Institute of Technology, 92 West Dazhi Str., Harbin, Heilongjiang, 150001, P.R. China.
authors: Xiqiang
authors: X
authors: Huang
authors: Department of Physics, Harbin Institute of Technology, 92 West Dazhi Str., Harbin, Heilongjiang, 150001, P.R. China.
authors: Zhe
authors: Z
authors: Lü
mesh_terms: D004553:Electric Conductivity; D011211:Electric Power Supplies; D004563:Electrochemistry; D004566:Electrodes; D010087:Oxides / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*; D011221:Praseodymium / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D010087:Oxides; D011221:Praseodymium; D010100:Oxygen
keywords: ceramics; deactivation and recovery; electrochemistry; fuel cells; surface chemistry