Native Ligand Carbonization Renders Common Platinum Nanoparticles Highly Durable for Electrocatalytic Oxygen Reduction : Annealing Temperature Matters

© 2022 Wiley-VCH GmbH..

Current protocols for synthesizing monodisperse platinum (Pt) nanoparticles typically involve the use of hydrocarbon molecules as surface-capping ligands. Using Pt nanoparticles as catalysts for the oxygen reduction reaction (ORR), however, these ligands must be removed to expose surface sites. Here, highly durable ORR catalysts are realized without ligand removal; instead, the native ligands are converted into ultrathin, conformal graphitic shells by simple thermal annealing. Strikingly, the annealing temperature is a critical factor dictating the ORR performance of Pt catalysts. Pt nanoparticles treated at 500 °C show a very poor ORR activity, whereas those annealed at 700 °C become highly active along with exceptional stability. In-depth characterization reveals that thermal treatment from 500 to 700 °C gradually opens up the porosity in carbon shells through graphitization. Importantly, such graphitic-shell-coated Pt catalysts exhibit a superior ORR stability, largely retaining the activity after 20 000 cycles in a membrane electrode assembly. Moreover, this ligand carbonization strategy can be extended to modify commercial Pt/C catalysts with substantially enhanced stability. This work demonstrates the feasibility of boosting the ORR performance of common Pt nanoparticles by harnessing the native surface ligands, offering a robust approach of designing highly durable catalysts for proton-exchange-membrane fuel cells.

Medienart:

E-Artikel

Erscheinungsjahr:

2022

Erschienen:

2022

Enthalten in:

Zur Gesamtaufnahme - volume:34

Enthalten in:

Advanced materials (Deerfield Beach, Fla.) - 34(2022), 26 vom: 14. Juli, Seite e2202743

Sprache:

Englisch

Beteiligte Personen:

Li, Zhicheng [VerfasserIn]
Zou, Jinxiang [VerfasserIn]
Xi, Xiangyun [VerfasserIn]
Fan, Pengshuo [VerfasserIn]
Zhang, Yi [VerfasserIn]
Peng, Ye [VerfasserIn]
Banham, Dustin [VerfasserIn]
Yang, Dong [VerfasserIn]
Dong, Angang [VerfasserIn]

Links:

Volltext

Themen:

Durability
Journal Article
Ligand carbonization
Membrane electrode assembly
Oxygen reduction reaction
Platinum nanoparticles

Anmerkungen:

Date Revised 01.07.2022

published: Print-Electronic

Citation Status PubMed-not-MEDLINE

doi:

10.1002/adma.202202743

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM33955648X