Key Structural Transformations and Kinetics of Pt Nanoparticles in PEFC Pt/C Electrocatalysts by a Simultaneous Operando Time-Resolved QXAFS–XRD Technique

Autor:	Kotaro Higashi, Yusuke Yoshida, Yasuhiro Iwasawa, Gabor Samjeské, Tomoya Uruga, Shinobu Takao, Tomohiro Sakata, Takao Gunji, Oki Sekizawa, Takuma Kaneko, Xiao Zhao
Rok vydání:	2018
Předmět:	Valence (chemistry) Materials science Polymer electrolyte fuel cell Coordination number Kinetics Simultaneous operando time-resolved QXAFS‒XRD measurements Pt/C cathode catalyst 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Durability Transient voltage suppressor Catalysis Cathode 0104 chemical sciences law.invention Performance and durability Reaction rate constant Chemical engineering law Mechanism and structural kinetics 0210 nano-technology
Zdroj:	Topics in Catalysis. 61:889-901
ISSN:	1572-9028 1022-5528
Popis:	This account article treats with the key structural transformations and kinetics of Pt nanoparticles in Pt/C cathode catalysts under transient voltage operations (0.4 VRHE→1.4 VRHE→0.4 VRHE) by simultaneous operando time-resolved QXAFS–XRD measurements, summarizing and analyzing our previous kinetic data in more detail and discussing on the key reaction steps and rate constants for the performance and durability of polymer electrolyte fuel cells (PEFC). The time-resolved QXAFS–XRD measurements were conducted at each acquisition time of 20 ms, while measuring the current/charge of the PEFC. The rate constants for the transient responses of Pt valence, CN(Pt–O) (CN: coordination number), CN(Pt–Pt), and Pt metallic-phase core size under the transient voltage operations were determined by the combined time-resolved QXAFS‒XRD technique. The relationship of the structural kinetics with the performance and durability of the PEFC Pt/C was also documented as key issues for the development of next-generation PEFCs. The present account emphasizes the time-resolved QXAFS and XRD techniques to be a powerful technique to analyze directly the structural and electronic change of metal nanoparticles inside PEFC under the operating conditions.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::a82cd096b786da398f1869bbd38b1659 https://doi.org/10.1007/s11244-018-0934-1 Zobrazit plný text záznamu Plný text ve formátu PDF Plný text ve formátu HTML
Nepřihlášeným uživatelům se plný text nezobrazuje	K zobrazení výsledku je třeba se přihlásit.