Unraveling and Resolving the Inconsistencies in Tafel Analysis for Hydrogen Evolution Reactions
University of California, Los Angeles · California NanoSystems Institute
Abstract
The Tafel slope represents a critical kinetic parameter for mechanistic studies of electrochemical reactions, including the hydrogen evolution reaction (HER). Linear fitting of the polarization curve in a N2-saturated electrolyte is commonly used to determine Tafel slopes, which is, however, frequently plagued with inconsistencies. Our systematic studies reveal that the Tafel slopes derived from this approach are loading- and potential-dependent, and could substantially exceed the theoretical limits. Our analyses indicate that this discrepancy is largely attributed to the locally trapped HER-generated H2 in the catalyst layer. A non-negligible hydrogen oxidation reaction (HOR) current more prominently offsets…
Citation impact
- FWCI
- 15.57
- Percentile
- 100%
- References
- 43
Authors
6Topics & keywords
- Tafel equation
- Overpotential
- Electrolyte
- Catalysis
- Chemistry
- Polarization (electrochemistry)
- Hydrogen
- Electrochemistry