Pore Structural Characterization of Fuel Cell Layers Using Integrated Mercury Porosimetry and Computerized X-ray Tomography

Malik, Shoaib; Smith, Linda; Sharman, Joanatham; Holt, Elizabeth M.; Rigby, Sean P.

Abstract

The pore structure of the cathode catalyst layer of proton-exchange membrane (PEM) fuel cells is a major factor influencing cell performance. The nanostructure of the catalyst layer has been probed using a novel combination of mercury porosimetry with computerized X-ray tomography (CXT), even though the nanopores were below the nominal CXT resolution. The method allows probing of the macroscopic spatial variability in the accessibility of the nanostructure. In particular, mercury entrapment within the catalyst layer showed a pronounced regular spatial patterning corresponding to the already higher X-ray absorbing regions of the fresh catalyst layer. The initial, greater X-ray absorption was due to a higher local concentration of carbon-supported platinum catalyst. This was due to segregation of ionomer away from these areas caused by the particular screen printing catalyst layer deposition method used, which both enhanced the accessibility of the origin regions and, concomitantly, reduced the accessibility of the destination regions.

Citation

Malik, S., Smith, L., Sharman, J., Holt, E. M., & Rigby, S. P. (2016). Pore Structural Characterization of Fuel Cell Layers Using Integrated Mercury Porosimetry and Computerized X-ray Tomography. Industrial & Engineering Chemistry Research, 55(41), 10850-10859. https://doi.org/10.1021/acs.iecr.6b01617

• Journal Article Type: Article
• Acceptance Date: Sep 28, 2016
• Online Publication Date: Oct 5, 2016
• Publication Date: Oct 19, 2016
• Deposit Date: Nov 21, 2016
• Publicly Available Date: Nov 21, 2016
• Journal: Industrial & Engineering Chemistry Research
• Print ISSN: 0888-5885
• Electronic ISSN: 1520-5045
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 55
• Issue: 41
• Pages: 10850-10859
• DOI: https://doi.org/10.1021/acs.iecr.6b01617
• Public URL: https://nottingham-repository.worktribe.com/output/822668
• Publisher URL: http://pubs.acs.org/doi/abs/10.1021/acs.iecr.6b01617
• Additional Information: This document is the Accepted Manuscript version of a Published Work that appeared in final form in Industrial and Engineering Chemical Research, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/acs.iecr.6b01617