3D Imaging of Catalyst Support Corrosion in Polymer Electrolyte Fuel Cells
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- 作者：Hendrik Schulenburg ; Bernhard Schwanitz ; Nicolas Linse ; Gu虉nther G. Scherer ; A. Wokaun ; Julijana Krbanjevic ; Roman Grothausmann ; Ingo Manke
- 刊名：Journal of Physical Chemistry C
- 出版年：2011
- 出版时间：July 28, 2011
- 年：2011
- 卷：115
- 期：29
- 页码：14236-14243
- 全文大小：1115K
- 年卷期：v.115,no.29(July 28, 2011)
- ISSN：1932-7455
文摘
During the lifetime of a polymer electrolyte fuel cell, the pore structure of the Pt/C catalyst layer may change as a result of carbon corrosion. Three-dimensional visualization of porosity changes is important to understand the origin of fuel cell performance deterioration. A focused ion beam/scanning electron microscopy (FIB/SEM) approach was adopted together with electron tomographic studies to visualize the three-dimensional pore structure of a Pt/C catalyst. In the case of pristine catalyst layers, the pores form an interconnected network. After 1000 start-up/shut-down cycles, severe carbon corrosion leads to a collapse of the support structure. The porosity of the degraded catalyst layer shrinks drastically, resulting in a structure of predominantly isolated pores. These porosity changes hinder the mass transport in the catalyst layer, consequently leading to a substantial loss of fuel cell performance. FIB/SEM serial sectioning and electron tomography allows three-dimensional imaging of the catalyst pore structure, which is a prerequisite for modeling and optimizing mass transport in catalyst layers.