Boosting Oxygen Reduction at Pt(111)|Proton Exchange Ionomer Interfaces through Tuning the Microenvironment Water Activity
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Title: | Boosting Oxygen Reduction at Pt(111)|Proton Exchange Ionomer Interfaces through Tuning the Microenvironment Water Activity |
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Authors: | Xu, Yujun | Zhang, Lulu | Chen, Wei | Cui, Haowen | Cai, Jun | Chen, Yanxia | Feliu, Juan M. | Herrero, Enrique |
Research Group/s: | Electroquímica de Superficies |
Center, Department or Service: | Universidad de Alicante. Departamento de Química Física | Universidad de Alicante. Instituto Universitario de Electroquímica |
Keywords: | Pt(111) | Ionomer | Adsorption | Water activity | Oxygen reduction reaction |
Issue Date: | 16-Jan-2024 |
Publisher: | American Chemical Society |
Citation: | ACS Applied Materials & Interfaces. 2024, 16(4): 4540-4549. https://doi.org/10.1021/acsami.3c14208 |
Abstract: | A proton exchange ionomer is one of the most important components in membrane electrode assemblies (MEAs) of polymer electrolyte membrane fuel cells (PEMFCs). It acts as both a proton conductor and a binder for nanocatalysts and carbon supports. The structure and the wetting conditions of the MEAs have a great impact on the microenvironment at the three-phase interphases in the MEAs, which can significantly influence the electrode kinetics such as the oxygen reduction reaction (ORR) at the cathode. Herein, by using the Pt(111)|X ionomer interface as a model system (X = Nafion, Aciplex, D72), we find that higher drying temperature lowers the onset potential for sulfonate adsorption and reduces apparent ORR current, while the current wave for OHad formation drops and shifts positively. Surprisingly, the intrinsic ORR activity is higher after properly correcting the blocking effect of Pt active sites by sulfonate adsorption and the poly(tetrafluoroethylene) (PTFE) skeleton. These results are well explained by the reduced water activity at the interfaces induced by the ionomer/PTFE, according to the mixed potential effect. Implications for how to prepare MEAs with improved ORR activity are provided. |
Sponsor: | This work was supported by the National Natural Science Foundation of China (Nos. 21972131, 22372154). E.H. gratefully acknowledges the International Professorship by USTC and financial support from the Ministerio de Ciencia e Innovación (Project PID2022-137350NB-I00). |
URI: | http://hdl.handle.net/10045/139927 |
ISSN: | 1944-8244 (Print) | 1944-8252 (Online) |
DOI: | 10.1021/acsami.3c14208 |
Language: | eng |
Type: | info:eu-repo/semantics/article |
Rights: | © 2024 American Chemical Society |
Peer Review: | si |
Publisher version: | https://doi.org/10.1021/acsami.3c14208 |
Appears in Collections: | INV - EQSUP - Artículos de Revistas |
Files in This Item:
File | Description | Size | Format | |
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Xu_etal_2024_ACSApplMaterInterfaces_final.pdf | Versión final (acceso restringido) | 3,53 MB | Adobe PDF | Open Request a copy |
Xu_etal_2024_ACSApplMaterInterfaces_preprint.pdf | Preprint (acceso abierto) | 1,98 MB | Adobe PDF | Open Preview |
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