Design and Impact: Navigating the Electrochemical Characterization Methods for Supported Catalysts.

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Proton exchange membrane fuel cells (PEMFCs) require improved oxygen reduction reaction (ORR) catalyst efficiency and durability for hydrogen energy applications.
• Traditional characterization methods like rotating disk electrodes (RDE) and membrane electrode assemblies (MEAs) have limitations in assessing supported catalysts under relevant conditions.

Purpose of the Study:

• To investigate the impact of electrochemical characterization method design on intrinsic catalyst activity measurements.
• To evaluate advanced techniques for more accurate assessment of ORR catalysts.

Main Methods:

• Review of established methods: rotating disk electrodes (RDE), rotating ring disk electrodes (RRDE), and membrane electrode assemblies (MEAs).
• Analysis of emerging techniques: ultramicroelectrodes, floating electrodes (FE), and gas diffusion electrodes (GDEs).

Main Results:

• RDE and RRDE methods are limited by mass transport conditions at high current densities.
• Floating electrode (FE) technique provides reliable experimental data under application-relevant high-mass transport conditions for intrinsic ORR activity.
• Gas diffusion electrodes (GDEs) serve as effective bridges between RDE and MEA experiments.

Conclusions:

• Methodological choices significantly influence intrinsic catalyst activity measurements for ORR.
• FE and GDE methods offer enhanced capabilities for catalyst characterization, improving understanding and optimization of fuel cell and electrolyzer technologies.