Machine Learning-Driven Prediction of Electrochemical Promotion in the Reverse Water Gas Shift Reaction.

Abstract

Electrochemical promotion of catalysis (EPOC) provides an effective and versatile strategy to enhance catalytic activity, selectivity, and stability in the reverse water-gas shift (RWGS) reaction, facilitating efficient CO2 hydrogenation to syngas under milder conditions. However, predicting EPOC results using novel catalytic materials under diverse conditions remains challenging. This study introduces a machine learning framework to predict electrochemical promotion behavior and the rate enhancement ratios (ρ), i.e., ratio between promoted and unpromoted reaction rate, based on the selected catalyst, reaction, and electrochemical condition descriptors. Several classification and regression models were trained and tested using a data set compiled from previous studies. The best-performing random forest (RF) and extreme gradient boosting (XGB) models were validated with new experimental data collected from systems employing lithium lanthanum titanate (LLTO) solid electrolyte and Pt-ZnO catalysts, achieving an R2 of 0.97 and a mean squared error (MSE) of 0.01. This data-driven approach is interpretable, generalizable to other catalytic systems, and provides a powerful tool for advancing the development of catalytic materials for EPOC in RWGS reactions.