Computational Modeling of Catalysis by MXenes: Key Aspects

ConspectusThe field of two-dimensional (2D) carbides and nitrides (MXenes) has increased by leaps and bounds since the isolation of Ti3C2Tx, the first MXene, in 2011. MXenes offer high specific surface area and a unique electronic structure leading to properties with a broad potential of applications. For instance, MXenes as heterogeneous catalysts may constitute a strategic response to the challenge posed by the scarcity and elevated costs of noble metals involved in many industrial catalysts. In fact, the exploration of MXenes in heterogeneous catalysis has opened new avenues for the application of these materials, expanding their role beyond traditional material applications. This Account focuses on the exploration of MXenes as catalysts for the capture and conversion of CO2 from a computational materials science perspective. It systematically reviews our contributions in first-principles modeling going beyond the standard extended surface models. It starts by briefly discussing the kinetic phase diagrams as a useful tool to predict the practical conditions for CO2 activation by on MXenes. The ease of CO2 activation and dissociation on MXenes makes them feasible catalysts for CO2 conversion, for instance through the reverse water gas shift reaction. Progresses in this direction are discussed in this Account including key aspects affecting the catalytic performance of MXenes revealed by multiscale, mean-field kinetic, and kinetic Monte Carlo simulations. Overall, our computational strategy combining first-principles calculations, kinetic phase diagrams, and multiscale modeling provides a workflow to scrutinize the catalytic capability of new MXenes, shedding light into the predicted behavior, ultimately providing rational structure–property relationships which drive experimentalists toward the best possible candidates.