Simultaneous Operando Time-Resolved XAFS–XRD Measurements of a Pt/C Cathode Catalyst in Polymer Electrolyte Fuel Cell under Transient Potential Operations
| Autor: | Kotaro Higashi, Tomohiro Sakata, Yasuhiro Iwasawa, Takuma Kaneko, Tomoya Uruga, Oki Sekizawa, Yusuke Yoshida |
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| Rok vydání: | 2017 |
| Předmět: |
Reaction mechanism
Materials science General Chemical Engineering Analytical chemistry 02 engineering and technology Electrolyte Simultaneous operando time-resolved QXAFS−XRD measurements 010402 general chemistry 01 natural sciences Dissociation (chemistry) law.invention Reaction rate constant law Environmental Chemistry Surface layer Renewable Energy Sustainability and the Environment Pt/C cathode catalyst General Chemistry 021001 nanoscience & nanotechnology Cathode 0104 chemical sciences Anode X-ray absorption fine structure Polymer electrolyte fuel cell (PEFC) Transient response structural and electronic transformations 0210 nano-technology |
| Zdroj: | ACS Sustainable Chemistry & Engineering. 5:3631-3636 |
| ISSN: | 2168-0485 |
| Popis: | We have succeeded in simultaneous operando time-resolved quick X-ray absorption fine structure (QXAFS)–X-ray diffraction (XRD) measurements at each acquisition time of 20 ms for a Pt/C cathode catalyst in a polymer electrolyte fuel cell (PEFC), while measuring the current/charge of the PEFC during the transient voltage cyclic processes (0.4 VRHE → 1.4 VRHE → 0.4 VRHE) under H2(anode)–N2(cathode). The rate constants for Pt–O bond formation/dissociation, Pt charging/discharging, Pt–Pt bond dissociation/reformation, and decrease/increase of Pt metallic-phase core size under the transient potential operations were determined by the combined time-resolved QXAFS–XRD technique. The present study provides a new insight into the transient-response reaction mechanism and structural transformation in the Pt surface layer and bulk, which are relevant to the origin of PEFC activity and durability as key issues for the development of next-generation PEFCs. |
| Databáze: | OpenAIRE |
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