The Crucial Role of Rotation Speed on the Determination of Tafel Slopes of Electrocatalysts in Rotating Disk Electrode Experiments
Bibliographic record
Abstract
This article highlights the crucial influence of rotation speeds in determining the Tafel slopes of electrocatalysts in rotating disk electrode (RDE) experiments. As an exemplary system, we investigate catalytically active nickel oxide/oxyhydroxide films that were generated from the transformation of electrodeposited nickel selenide at Au-RDEs, under oxygen evolution reaction (OER) conditions in alkaline electrolytes at three different rotation rates (1600, 2500, and 4000 rpm). Tafel slopes were extracted using cyclic voltammetry (CV) and chronoamperometry (CA). Our results underline the benefit of higher rotation speed in overcoming undesired mass transport limitations. Additionally, we point out that using CA instead of CV methods is preferable for the extraction of kinetic parameters since CA ensures steady state conditions and simplifies data analysis. Furthermore, we highlight that rigorous determination of reaction mechanisms based on Tafel slopes is only appropriate if the boundary conditions of the Butler-Volmer formalism are fulfilled, and we recommend not using Tafel slopes as the single parameter to compare the activity of electrocatalysts if these are obtained at different experimental conditions. Instead, we suggest reporting relevant measurement parameters such as the rotation speed of the experiment, way of Ohmic drop compensation, electrode geometry, and the electrochemical method used for Tafel analysis alongside the calculated Tafel slopes. Doing so may allow comparison to literature-reported Tafel slopes if the data were determined under similar experimental conditions. Rather than focusing on individual values, trends between systematically modified catalysts or at different aging stages should be considered meaningful.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.004 | 0.014 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.002 | 0.002 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".