Understanding a Degradation Mechanism of Direct Methanol Fuel Cell Using TOF-SIMS and XPS
Understanding a Degradation Mechanism of Direct Methanol Fuel Cell Using TOF-SIMS and XPS
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DOI：
10.1021/jp0759372
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发表时间：
2008
影响因子：
3.7
通讯作者：
Youngsu Chung;C. Pak;G. Park;W. Jeon;Ji-Rae Kim;Yoonhoi Lee;Hyuk Chang;D. Seung
中科院分区：
文献类型：
--
作者：
Youngsu Chung;C. Pak;G. Park;W. Jeon;Ji-Rae Kim;Yoonhoi Lee;Hyuk Chang;D. Seung
用X射线光电子能谱(XPS)和飞行时间二次离子质谱仪(TOF-SIMS)对老化膜电极组件(MEA)的催化层进行了研究，以了解直接甲醇燃料电池中单电池性能的退化机理。随着价带的变化，PtRu阳极催化层中的金属组分显著减少，性能下降。在耐久性试验中发现，在电场梯度作用下，Ru和Plu被驱动到阴极。TOF-SIMS的质量分辨成像技术结合剥离方法表明，从阳极到阴极的Ru不是均匀分布在阴极催化层内，而是更多地积累在催化层的表面，即与气体扩散层的界面上。
The catalyst layers, which were obtained from the aged membrane electrode assemblies (MEAs) showing performance loss, 17%, 37%, 45% as compared with that from the pristine MEA were investigated using X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectroscopy (TOF-SIMS) to understand the degradation mechanism of single-cell performance in direct methanol fuel cell. The metallic components in the PtRu anode catalyst layer was decreased significantly with the performance drop revealed from the change of the valance bands. It has been found that ruthenium and platinum were driven to the cathode by the gradient of electric field during the durability test. From the mass-resolved imaging technique of TOF-SIMS combined with a peel-off method, it was indicated that the traveled ruthenium from anode to cathode was not uniformly distributed within the cathode catalyst layer, but more accumulated at the surface of the catalyst layer, that is, the interface with the gas diffusion layer....