Following Adsorbed Intermediates on a Platinum Gas Diffusion Electrode in H3PO3-Containing Electrolytes Using in Situ X-ray Absorption Spectroscopy
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22310%2F22%3A43924270" target="_blank" >RIV/60461373:22310/22:43924270 - isvavai.cz</a>
Result on the web
<a href="https://doi.org/10.1021/acscatal.2c02630" target="_blank" >https://doi.org/10.1021/acscatal.2c02630</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1021/acscatal.2c02630" target="_blank" >10.1021/acscatal.2c02630</a>
Alternative languages
Result language
angličtina
Original language name
Following Adsorbed Intermediates on a Platinum Gas Diffusion Electrode in H3PO3-Containing Electrolytes Using in Situ X-ray Absorption Spectroscopy
Original language description
One of the challenges of high-temperature polymer electrolyte membrane fuel cells is the poisoning of the Pt catalyst with H3PO4. H3PO4 is imbibed into the routinely used polybenzimidazole-based membranes, which facilitate proton conductivity in the temperature range of 120-200 °C. However, when leached out of the membrane by water produced during operation, H3PO4 adsorbs on the Pt catalyst surface, blocking the active sites and hindering the oxygen reduction reaction (ORR). The reduction of H3PO4 to H3PO3, which occurs at the anode due to a combination of a low potential and the presence of gaseous H2, has been investigated as an additional important contributing factor to the observed poisoning effect. H3PO3 has an affinity toward adsorption on Pt surfaces even greater than that of H2PO4-. In this work, we investigated the poisoning effect of both H3PO3 and H3PO4 using a half-cell setup with a gas diffusion electrode under ambient conditions. By means of in situ X-ray absorption spectroscopy, it was possible to follow the signature of different species adsorbed on the Pt nanoparticle catalyst (H, O, H2PO4-, and H3PO3) at different potentials under ORR conditions in various electrolytes (HClO4, H3PO4, and H3PO3). It was found that H3PO3 adsorbs in a pyramidal configuration P(OH)3 through a Pt-P bond. The competition between H3PO4 and H3PO3 adsorption was studied, which should allow for a better understanding of the catalyst poisoning mechanism and thus assist in the development of strategies to mitigate this phenomenon in the future by minimizing H3PO3 generation by, for example, improved catalyst design or adapted operation conditions or changes in the electrolyte composition. © 2022 American Chemical Society.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10405 - Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis)
Result continuities
Project
<a href="/en/project/GC19-02964J" target="_blank" >GC19-02964J: Electrochemistry of Pt - P oxoacids interface as a key to understanding of high temperature PEM fuel cells performance</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2022
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
ACS Catalysis
ISSN
2155-5435
e-ISSN
2155-5435
Volume of the periodical
12
Issue of the periodical within the volume
18
Country of publishing house
US - UNITED STATES
Number of pages
13
Pages from-to
11472-11484
UT code for WoS article
000852640500001
EID of the result in the Scopus database
2-s2.0-85138085721