Bayesian data analysis reveals no preference for cardinal Tafel slopes in CO2 reduction electrocatalysis

The Tafel slope is a key parameter often quoted to characterize the efficacy of an electrochemical catalyst. In this paper, we develop a Bayesian data analysis approach to estimate the Tafel slope from experimentally-measured current-voltage data. Our approach obviates the human intervention require...

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Bibliographic Details
Main Authors: Limaye, Aditya M, Zeng, Joy, Willard, Adam P., Manthiram, Karthish
Other Authors: Massachusetts Institute of Technology. Department of Chemical Engineering
Format: Article
Published: Springer Science and Business Media LLC 2021
Online Access:https://hdl.handle.net/1721.1/132626
Description
Summary:The Tafel slope is a key parameter often quoted to characterize the efficacy of an electrochemical catalyst. In this paper, we develop a Bayesian data analysis approach to estimate the Tafel slope from experimentally-measured current-voltage data. Our approach obviates the human intervention required by current literature practice for Tafel estimation, and provides robust, distributional uncertainty estimates. Using synthetic data, we illustrate how data insufficiency can unknowingly influence current fitting approaches, and how our approach allays these concerns. We apply our approach to conduct a comprehensive re-analysis of data from the CO₂ reduction literature. This analysis reveals no systematic preference for Tafel slopes to cluster around certain "cardinal values” (e.g. 60 or 120 mV/decade). We hypothesize several plausible physical explanations for this observation, and discuss the implications of our finding for mechanistic analysis in electrochemical kinetic investigations.