TY - JOUR
T1 - Operando Soft X-ray Absorption Spectroscopic Study on a Solid Oxide Fuel Cell Cathode during Electrochemical Oxygen Reduction
AU - Nakamura, Takashi
AU - Oike, Ryo
AU - Kimura, Yuta
AU - Tamenori, Yusuke
AU - Kawada, Tatsuya
AU - Amezawa, Koji
N1 - Funding Information:
This work was supported by CREST, JST (grant No. JPMJCR11C1) and JSPS Grant-in-Aid for Scientific Research No. 24656374. The synchrotron radiation experiments were performed at the BL27SU of SPring-8 with the approval of the Japan Synchrotron Radiation Research Institute (JASRI; Proposal Nos. 2013A1716, 2013B148, and 2014A1452).
Publisher Copyright:
© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2017/5/9
Y1 - 2017/5/9
N2 - An operando soft X-ray absorption spectroscopic technique, which enabled the analysis of the electronic structures of the electrode materials at elevated temperature in a controlled atmosphere and electrochemical polarization, was established and its availability was demonstrated by investigating the electronic structural changes of an La2NiO4+δ dense-film electrode during an electrochemical oxygen reduction reaction. Clear O K-edge and Ni L-edge X-ray absorption spectra could be obtained below 773 K under an atmospheric pressure of 100 ppm O2/He, 0.1 % O2/He, and 1 % O2 He gas mixtures. Considerable spectral changes were observed in the O K-edge X-ray absorption spectra upon changing the Po2 and application of electrical potential, whereas only small spectral changes were observed in Ni L-edge X-ray absorption spectra. A pre-edge peak of the O K-edge X-ray absorption spectra, which reflects the unoccupied partial density of states of Ni 3d–O 2p hybridization, increased or decreased with cathodic or anodic polarization, respectively. The electronic structural changes of the outermost orbital of the electrode material due to electrochemical polarization were successfully confirmed by the operando X-ray absorption spectroscopic technique developed in this study.
AB - An operando soft X-ray absorption spectroscopic technique, which enabled the analysis of the electronic structures of the electrode materials at elevated temperature in a controlled atmosphere and electrochemical polarization, was established and its availability was demonstrated by investigating the electronic structural changes of an La2NiO4+δ dense-film electrode during an electrochemical oxygen reduction reaction. Clear O K-edge and Ni L-edge X-ray absorption spectra could be obtained below 773 K under an atmospheric pressure of 100 ppm O2/He, 0.1 % O2/He, and 1 % O2 He gas mixtures. Considerable spectral changes were observed in the O K-edge X-ray absorption spectra upon changing the Po2 and application of electrical potential, whereas only small spectral changes were observed in Ni L-edge X-ray absorption spectra. A pre-edge peak of the O K-edge X-ray absorption spectra, which reflects the unoccupied partial density of states of Ni 3d–O 2p hybridization, increased or decreased with cathodic or anodic polarization, respectively. The electronic structural changes of the outermost orbital of the electrode material due to electrochemical polarization were successfully confirmed by the operando X-ray absorption spectroscopic technique developed in this study.
KW - X-ray absorption spectroscopy
KW - cathodes
KW - electrochemistry
KW - electronic structure
KW - fuel cells
UR - http://www.scopus.com/inward/record.url?scp=85017566387&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85017566387&partnerID=8YFLogxK
U2 - 10.1002/cssc.201700237
DO - 10.1002/cssc.201700237
M3 - Article
C2 - 28301085
AN - SCOPUS:85017566387
VL - 10
SP - 2008
EP - 2014
JO - ChemSusChem
JF - ChemSusChem
SN - 1864-5631
IS - 9
ER -