On the micro-, meso-, and macroporous structures of polymer electrolyte membrane fuel cell catalyst layers

Download
  1. (PDF, 569 KB)
  2. Get@NRC: On the micro-, meso-, and macroporous structures of polymer electrolyte membrane fuel cell catalyst layers (Opens in a new window)
DOIResolve DOI: http://doi.org/10.1021/am900600y
AuthorSearch for: ; Search for: ; Search for: ; Search for: ; Search for: ; Search for:
TypeArticle
Journal titleApplied Materials and Interfaces
Volume2
Issue2
Pages375384; # of pages: 10
SubjectN2 adsorption; microstructure; catalyst layer; Ketjen Black; Vulcan XC-72
AbstractIn this work, N2 adsorption was employed to investigate the effects of carbon support, platinum, and ionomer loading on the microstructure of polymer electrolyte membrane fuel cell catalyst layers (CLs). Brunauer-Emmett-Teller and t-plot analyses of adsorption isotherms and pore-size distributions were used to study the microstructure of carbon supports, platinum/carbon catalyst powders, and three-component platinum/carbon/ionomer CLs. Two types of carbon supports were chosen for the investigation: Ketjen Black and Vulcan XC-72. CLs with a range of Nafion ionomer loadings were studied in order to evaluate the effect of an ionomer on the CL microstructure. Regions of adsorption were differentiated into micropores associated with the carbon primary particles (<2 nm), mesopores ascribed to the void space inside agglomerates (2-20 nm), and meso- to macroporous space inside aggregates of agglomerates (>50 nm). Ketjen Black was found to possess a significant fraction of micropores, 25% of the total pore volume, in contrast to Vulcan XC-72, for which the corresponding fraction of micropores was 15% of the total pore volume. The microstructure of the carbon support was found to be a significant factor in the formation of the microstructure in the three-component CLs, serving as a rigid porous framework for distribution of platinum and the ionomer. It was found that platinum particle deposition on Ketjen Black occurs in, or at the mouth of, the support’s micropores, thus affecting its effective microporosity, whereas platinum deposition on Vulcan XC-72 did not significantly affect the support’s microstructure. The codeposition of ionomer in the CL strongly influenced its porosity, covering pores < 20 nm, which are ascribed to the pores within the primary carbon particles (pore sizes < 2 nm) and to the pores within agglomerates of the particles (pore sizes of 2-20 nm).
Publication date
LanguageEnglish
AffiliationNRC Institute for Fuel Cell Innovation; National Research Council Canada
Peer reviewedYes
NPARC number17101716
Export citationExport as RIS
Report a correctionReport a correction
Record identifier8d7ec613-77f1-4527-a418-6fff8cc416a9
Record created2011-03-09
Record modified2016-05-09
Bookmark and share
  • Share this page with Facebook (Opens in a new window)
  • Share this page with Twitter (Opens in a new window)
  • Share this page with Google+ (Opens in a new window)
  • Share this page with Delicious (Opens in a new window)