X-ray tomography of catalyst layer of proton exchange membrane fuel cell

YUHUNG HSU
Project Completed

Scientific Case

This work aims to investigate the relationship between the microstructure of catalyst layer and its performance. Catalyst layer is area located near by the membrane of proton exchange membrane fuel cell (PEMFC) and it stimulates the hydrogen gas to split up to hydrogen protons and electrons. The electrons go through the outside circuit from cathode to anode but not go through the membrane directly. This current flow can be used in any electric device. The microstructure of catalyst influences the efficiency of chemical reaction. During the producing of PEMFC, the membrane, catalyst layer and electrode are compressed to form one stack. However, the microstructure of catalyst layer changes after removing the compression. In order to better understand the microstructure of catalyst layer, X-ray tomography can be used and samples are prepared by Johnson Matthey Technology Centre. Imagines of 3D microstructure, the active elements and the distribution of the active elements of catalyst layer will be obtained from X-ray microCT( Nikon Metris 225KV machine) and the imagines will be analysed by the software, AVIZO. Comparing the analysed database from AVIZO, the relationship of microstructure and performance of catalyst could be obtained.
Ceramics

Experiment Design

microstructure of catalyst layer

100-1000 microns
Scanners and Rigs
Xradia MicroXCT
15

Sample & Safety

2
Radioactive

Scan Records

Xradia MicroXCT
40
250
4x
Scan dates: to 2011-04-18 for 2 scans.
Xradia MicroXCT
80
10
20
2011-04-25
Scan dates: 2011-04-25 to 2011-04-28 for 2 scans.
Xradia MicroXCT
80
10
40
2011-06-20
1 scans.
Xradia MicroXCT
140
10
40
2011-07-14
1 scans.

Project Report

Login