Coupling covariance matrix adaptation with continuum modeling for determination of kinetic parameters associated with electrochemical CO2 reduction
Kaitlin Rae M. Corpus, Justin C. Bui, Aditya Limaye, L. M. Pant, Karthish Manthiram, Adam Z. Weber, Alexis T. Bell
Abstract
In electrocatalysis, the rate of a reaction as a function of applied potential is governed by the Tafel equation, which depends on two parameters: the Tafel slope and the exchange current density ( i 0 ). However, current methods to determine these parameters involve subjective removal of data due to the convoluted effects of mass transfer and competitive surface or bulk reactions, resulting in unquantifiable uncertainty. To overcome this challenge, we couple covariance matrix adaptation with a continuum model of CO 2 reduction (CO 2 R) that explicitly deconvolutes non-kinetic effects to extract kinetic parameters associated with 26 literature datasets of CO 2 R over Ag and Sn catalysts. The fitted kinetic parameters do not converge to a unique set of values, and the Tafel slope and i 0 possess an apparent correlation, which we suggest is a consequence of variations in catalyst preparation methods. This work facilitates rigorous benchmarking of electrocatalysts in systems where mass transfer is relevant.