Mitigating Pt Loss in Polymer Electrolyte Membrane Fuel Cell Cathode Catalysts Using Graphene Nanoplatelet Pickering Emulsion Processing

Carbon‐supported Pt nanoparticles are the leading catalysts for the cathode oxygen reduction reaction (ORR) in polymer electrolyte membrane fuel cells. However, these ORR catalysts suffer from poor electrochemical durability, particularly the loss of electrochemical surface area (ECSA) due to Pt nan...

Full description

Saved in:
Bibliographic Details
Published in:Advanced functional materials 2022-10, Vol.32 (43), p.n/a
Main Authors: Park, Kyu‐Young, Sweers, Matthew E., Berner, Ulrich, Hirth, Erhard, Downing, Julia R., Hui, Janan, Mailoa, Jonathan, Johnston, Christina, Kim, Soo, Seitz, Linsey C., Hersam, Mark C.
Format: Article
Language:English
Subjects:
accelerated stability tests
Accelerated tests
Agglomeration
Basal plane
Carbon
Catalysts
Cell cathodes
Chemical reduction
Density functional theory
Dissolution
Durability
electrochemical surface area
Electrodes
Electrolytes
Electrolytic cells
Ethyl cellulose
Graphene
Materials science
membrane electrode assemblies
Nanoparticles
Oxygen reduction reactions
Polymers
Proton exchange membrane fuel cells
rotating disc electrodes
Rotating disks
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Carbon‐supported Pt nanoparticles are the leading catalysts for the cathode oxygen reduction reaction (ORR) in polymer electrolyte membrane fuel cells. However, these ORR catalysts suffer from poor electrochemical durability, particularly the loss of electrochemical surface area (ECSA) due to Pt nanoparticle dissolution and agglomeration. Here, Pt loss is mitigated through a Pickering emulsion‐processing strategy that employs graphene nanoplatelet dispersions stabilized by the polymer ethyl cellulose. The resulting graphene‐Pt/Vulcan carbon (Pt/C) catalysts exhibit superior durability and ECSA retention throughout an accelerated stress test compared with a commercial Pt/C standard catalyst, both in a diagnostic‐rotating disc electrode setup and in a membrane electrode assembly full cell. These graphene‐Pt/C catalysts also improve durability at high‐voltage conditions, providing further evidence of their exceptional electrochemical stability. Consistent with density functional theory calculations, postelectrochemical characterization reveals that Pt nanoparticles localize at graphene defects both on the basal plane and especially at the edges of the graphene nanoplatelets. Since this Pt nanoparticle localization suppresses Pt nanoparticle dissolution and agglomeration without hindering accessibility of the reactant species to the catalyst surface, the ORR performance under both idealized and practical experimental conditions shows significantly improved durability while maintaining high electrochemical activity. This study mitigates Pt loss for the cathode oxygen reduction reaction in polymer electrolyte membrane fuel cells through a Pickering emulsion‐processing strategy that employs graphene nanoplatelet dispersions stabilized by the polymer ethyl cellulose. The resulting catalysts exhibit superior durability and electrochemical surface area retention compared with incumbent approaches.
ISSN:1616-301X
1616-3028
DOI:10.1002/adfm.202205216