TY - JOUR
T1 - Operando Time-Resolved X-ray Absorption Fine Structure Study for Pt Oxidation Kinetics on Pt/C and Pt3Co/C Cathode Catalysts by Polymer Electrolyte Fuel Cell Voltage Operation Synchronized with Rapid O2 Exposure
AU - Ozawa, Saki
AU - Matsui, Hirosuke
AU - Ishiguro, Nozomu
AU - Tan, Yuanyuan
AU - Maejima, Naoyuki
AU - Taguchi, Masahiro
AU - Uruga, Tomoya
AU - Sekizawa, Oki
AU - Sakata, Tomohiro
AU - Nagasawa, Kensaku
AU - Higashi, Kotaro
AU - Tada, Mizuki
N1 - Funding Information:
This work was supported by the New Energy and Industrial Technology Development Organization of the Ministry of Economy, Trade and Industry Japan. XAFS measurements were performed at SPring-8 (Nos. 2014B7820 2015A7820, 2015B7820, 2016A7820, and 2016B7822). STEM-EDS was measured at High Voltage Electron Microscope Laboratory, Institute of Materials and Systems for Sustainability, Nagoya University, supported by Advanced Characterization Nanotechnology Platform of the Ministry of Education, Culture, Sports, Science and Technology, Japan.
Funding Information:
This work was supported by the New Energy and Industrial Technology Development Organization of the Ministry of Economy, Trade and Industry, Japan. XAFS measurements were performed at SPring-8 (Nos. 2014B7820, 2015A7820, 2015B7820, 2016A7820, and 2016B7822). STEM-EDS was measured at High Voltage Electron Microscope Laboratory, Institute of Materials and Systems for Sustainability, Nagoya University, supported by “Advanced Characterization Nanotechnology Platform” of the Ministry of Education, Culture, Sports, Science and Technology, Japan.
Publisher Copyright:
© 2018 American Chemical Society.
PY - 2018/7/5
Y1 - 2018/7/5
N2 - The oxidation of a cathode catalyst surface is one of the major factors for cathode catalyst degradation under polymer electrolyte fuel cell (PEFC) operating conditions; however, the oxidation kinetics of Pt cathode catalysts in a membrane electrode assembly with O2 has not been investigated. We have investigated operando Pt LIII-edge time-resolved X-ray absorption fine structure analysis for the Pt oxidation processes on Pt/C and Pt3Co/C cathode catalysts controlled by transient PEFC voltage operation (0.4 V → 0.7-1.0 V) synchronized with the rapid exchange of cathode gas (N2 → 10% O2 in N2). We plotted Pt valence and the coordination numbers of Pt-Pt and Pt-O bonds every 20 ms, and the rate constants of the structural parameters for the Pt oxidation were successfully estimated. The structural kinetics of the Pt oxidation at the cathode suggested differences in the Pt oxidation kinetics between the Pt/C and Pt3Co/C cathode catalysts, showing the kinetic control of the Pt oxidation rate by the alloying with Co to Pt.
AB - The oxidation of a cathode catalyst surface is one of the major factors for cathode catalyst degradation under polymer electrolyte fuel cell (PEFC) operating conditions; however, the oxidation kinetics of Pt cathode catalysts in a membrane electrode assembly with O2 has not been investigated. We have investigated operando Pt LIII-edge time-resolved X-ray absorption fine structure analysis for the Pt oxidation processes on Pt/C and Pt3Co/C cathode catalysts controlled by transient PEFC voltage operation (0.4 V → 0.7-1.0 V) synchronized with the rapid exchange of cathode gas (N2 → 10% O2 in N2). We plotted Pt valence and the coordination numbers of Pt-Pt and Pt-O bonds every 20 ms, and the rate constants of the structural parameters for the Pt oxidation were successfully estimated. The structural kinetics of the Pt oxidation at the cathode suggested differences in the Pt oxidation kinetics between the Pt/C and Pt3Co/C cathode catalysts, showing the kinetic control of the Pt oxidation rate by the alloying with Co to Pt.
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U2 - 10.1021/acs.jpcc.8b02541
DO - 10.1021/acs.jpcc.8b02541
M3 - Article
AN - SCOPUS:85048050414
VL - 122
SP - 14511
EP - 14517
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 26
ER -