Observation of Degradation of Pt and Carbon Support in Polymer Electrolyte Fuel Cell Using Combined Nano-X-ray Absorption Fine Structure and Transmission Electron Microscopy Techniques
| Autor: | Takashi Yamamoto, Yasuhiro Iwasawa, Takao Gunji, Shinobu Takao, Yusuke Yoshida, Tomohiro Sakata, Kotaro Higashi, Tomoya Uruga, Takuma Kaneko, Xiao Zhao, Oki Sekizawa, Gabor Samjeské |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Materials science
chemistry.chemical_element PEFC Pt/C cathode 02 engineering and technology Electrolyte Same-view imaging 010402 general chemistry 01 natural sciences Catalysis law.invention law Nano General Materials Science Nano-XAFS/STEM-EDS Degradation sequence 021001 nanoscience & nanotechnology Cathode 0104 chemical sciences X-ray absorption fine structure Pt and carbon degradations Chemical engineering chemistry Transmission electron microscopy 0210 nano-technology Carbon Layer (electronics) |
| Zdroj: | ACS Applied Materials & Interfaces. 10(33):27734-27744 |
| ISSN: | 1944-8244 |
| Popis: | It is hard to directly visualize spectroscopic and atomic-nanoscopic information on the degraded Pt/C cathode layer inside polymer electrolyte fuel cell (PEFC). However, it is mandatory to understand the preferential area, sequence, and relationship of the degradations of Pt nanoparticles and carbon support in the Pt/C cathode layer by directly observing the Pt/C cathode catalyst for the development of next-generation PEFC cathode catalysts. Here, the spectroscopic, chemical, and morphological visualization of the degradation of Pt/C cathode electrocatalysts in PEFC was performed successfully by a same-view combination technique of nano-X-ray absorption fine structure (XAFS) and transmission electron microscopy (TEM)/scanning TEM-energy-dispersive spectrometry (EDS) under a humid N2 atmosphere. The same-view nano-XAFS and TEM/STEM-EDS imaging of the Pt/C cathode of PEFC after triangular-wave 1.0-1.5 VRHE (startup/shutdown) accelerated durability test (tri-ADT) cycles elucidated the site-selective area, sequence, and relationship of the degradations of Pt nanoparticles and carbon support in the Pt/C cathode layer. The 10 tri-ADT cycles caused a carbon corrosion to reduce the carbon size preferentially in the boundary regions of the cathode layer with both electrolyte and holes/cracks, accompanied with detachment of Pt nanoparticles from the degraded carbon. After the decrease in the carbon size to less than 8 nm by the 20 tri-ADT cycles, Pt nanoparticles around the extremely corroded carbon areas were found to transform and dissolve into oxidized Pt2+-O4 species. |
| Databáze: | OpenAIRE |
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