Abstract
Unsupported iridium (Ir) nanoparticles, a benchmark catalyst in acidic electrolyzers, are investigated for oxygen evolution activity in rotating disk electrode (RDE) half-cells. Mercury underpotential deposition, used to evaluate the electrochemical surface areas (ECAs) of Ir, produces similar values prior to and following oxygen evolution testing and irreversible surface oxidation; stable ECA measurements allow for the study of site-specific activities prior to and following accelerated stress tests. Durability testing results in increasing activity losses due to particle growth at moderate potential and Ir dissolution at higher potential. Although the prolonged formation of oxygen bubbles may destabilize the catalyst layer, accelerated stress tests in hydrogen peroxide and formic acid confirm that the losses are primarily potential dependent. This study establishes RDE testing protocols for Ir in oxygen evolution. The observed durability losses have significant implications on acidic electrolyzers, particularly at low Ir loadings.
Original language | American English |
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Pages (from-to) | 883-892 |
Number of pages | 10 |
Journal | ECS Transactions |
Volume | 69 |
Issue number | 17 |
DOIs | |
State | Published - 2015 |
Event | Symposium on Polymer Electrolyte Fuel Cells 15, PEFC 2015 - 228th ECS Meeting - Phoenix, United States Duration: 11 Oct 2015 → 15 Oct 2015 |
Bibliographical note
Publisher Copyright:© The Electrochemical Society.
NREL Publication Number
- NREL/JA-5900-65547
Keywords
- durability testing
- iridium
- nanoparticles
- oxygen evolution