Student or educator? Sign up with your school email and get 6 months of Pro free.
Cited by 529

The DOI matches its Crossref record.

Molecular Oxygen Reduction in PEM Fuel Cells: Evidence for the Simultaneous Presence of Two Active Sites in Fe-Based Catalysts

Lefèvre, M., Dodelet, J. P., Bertrand, P.·2002·The Journal of Physical Chemistry B

Abstract

Three catalysts for the electroreduction of oxygen have been prepared by pyrolyzing between 400 and 1000 °C two iron precursors (Fe acetate or Fe porphyrin) adsorbed on a synthetic carbon made from the pyrolysis of PTCDA (perylene tetracarboxylic dianhydride) in a H 2 /NH 3 /Ar atmosphere. One Fe loading (0.2 wt %) has been used for the catalyst made from the salt precursor. Two Fe loadings (0.2 and 2.0 wt %) have been used for the catalyst made from the porphyrin precursor. These three catalysts have been analyzed by ToF SIMS and RDE (or GDE) in order to find correlations between ions detected by ToF SIMS and the catalytic activity. These correlations provide information about the number and the structure of the catalytic sites, which are active in these materials. By following the variation of FeN x C y + ions, it is found that (i) two different catalytic sites exist simultaneously in all catalysts made with the Fe salt or the Fe porphyrin; (ii) one site, named FeN 4 /C, is at the origin of three families of FeN x C y + ions: FeN 4 C y +, FeN 3 C y +, and FeN 1 C y + . The most representative ion of that site is FeN 4 C 8 + . The other site, labeled FeN 2 /C, is at the origin of the family of FeN 2 C y + ions. The most representative ion of that site is FeN 2 C 4 +; (iii) the abundance of FeN 2 /C goes through a maximum for catalysts pyrolyzed between 700 and 900 °C. When Fe acetate is the Fe precursor, FeN 2 /C may represent up to 80% of the catalytic sites, while this falls to a maximum of about 50% when Fe porphyrin is the precursor; (iv) FeN 2 /C is more electrocatalytically active than FeN 4 /C; (v) at high porphyrin loading (2.0 wt % Fe), the catalytic sites bound to the carbon support are covered with a porous layer of pyrolyzed Fe porphyrin.

Overview

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1021/jp020267f

Cites

Statistics

Verification

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Citations

Cited by

Metadata

Authors
Lefèvre, M., Dodelet, J. P., & Bertrand, P.
Venue
The Journal of Physical Chemistry B
Published
2002-07-27
Volume
106
Issue
34
Pages
8705-8713
ISSN
  • 1520-5207 (ISSN-L)
  • 1520-6106
OpenAlex
W2012671922
Cited by
529
References
0
FWCI
5.82
Type
journal article
Language
en
Open access
closed

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review

Data sources

Bibliographic data: Semantic Scholar, OpenAlex, Crossref.

Contains information from the Semantic Scholar Academic Graph Datasets, made available under the ODC Attribution License (ODC-BY 1.0).

Semantic Scholar’s data is described in: Kinney, R., et al. (2023). The Semantic Scholar Open Data Platform. arXiv:2301.10140.