The Oxygen Reduction Reaction on Pt and Ag Catalysts in Alkaline Media in Rrde and Half-Cell Setups

Rampf A, Braig M, Passerini S, Zeis R (2023)

Publication Type: Journal article

Publication year: 2023

Journal

ECS Meetings Abstracts The Electrochemical Society

Book Volume: MA2023-02

Pages Range: 2040-2040

Issue: 41

DOI: 10.1149/MA2023-02412040mtgabs

Abstract

Understanding the Oxygen Reduction Reaction (ORR) in alkaline media is essential to optimize alkaline fuel cells or metal-air batteries. The catalytic activity of various ORR catalysts has usually been evaluated via Rotating (Ring) Disk Electrode (R(R)DE) measurements. However, using an electrolyte with dissolved oxygen at low KOH concentrations measured in a microampere regime at room temperature does not reflect the real cell conditions.1 Yet, RRDE is still a valuable tool for probing the reaction pathway of catalysts in alkaline media. Our study combined traditional RRDE with Gas Diffusion Electrodes (GDEs) half-cell measurements using Pt and Ag catalysts.


The polarization curve of Pt-GDE exhibits a kink near 0.8 V vs. RHE leading to a significant potential drop. This specific feature can be explained by the RRDE results, which display an increased peroxide formation in that potential region due to the adsorption/desorption of hydroxyl adsorbates.2 However, Ag does not exhibit such behavior since the peroxide formation is below typical operating potentials. Depending on the operating conditions, Ag can catalyze the ORR more effectively than Pt in alkaline conditions while significantly reducing production costs. Furthermore, our study presents a general approach for evaluating ORR catalysts under experimentally challenging conditions such as elevated temperature and high KOH molarity.

Authors with CRIS profile

Roswitha Zeis

Involved external institutions

Helmholtz Institut Ulm DE Germany (DE) Karlsruhe Institute of Technology (KIT) DE Germany (DE)

How to cite

APA:

Rampf, A., Braig, M., Passerini, S., & Zeis, R. (2023). The Oxygen Reduction Reaction on Pt and Ag Catalysts in Alkaline Media in Rrde and Half-Cell Setups. ECS Meetings Abstracts, MA2023-02, 2040-2040. https://doi.org/10.1149/MA2023-02412040mtgabs

MLA:

Rampf, Alexander, et al. "The Oxygen Reduction Reaction on Pt and Ag Catalysts in Alkaline Media in Rrde and Half-Cell Setups." ECS Meetings Abstracts MA2023-02 (2023): 2040-2040.

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