(389e) A Roadmap for Modeling Single-Site (electro)Catalysts: A Combined Coupled Cluster, DFT and a Classical Force Field Approach

Single site catalysts supported on various substrates (e.g. graphene, carbon-nitrides, boron nitrides etc.) have recently emerged as promising catalysts for the oxygen reduction reaction (ORR). As the unique properties of these systems make them quite different from transition metals and alloy electrocatalysts, it is important to establish appropriate computational methods to accurately describe these materials. We use Cu-single atom active sites supported on a covalent triazine framework (CTF) as a case study to consider three distinct computational approaches. Using small cluster models, we first benchmark various DFT methods with coupled cluster theory to show that HSE06/D3 accurately describes the electronic structure. Next, we use hybrid DFT (HSE06/D3) calculations to determine the ORR mechanism by evaluating multiple possibilities for each reaction step. Finally, using DFT-derived force fields and classical Monte Carlo simulations, we estimate the solvation contributions using thermodynamic integration. Our results show that accurately benchmarking DFT methods (i.e. primary effects) and correctly incorporating solvation effects (i.e. secondary effects) are essential to describe the reactivity of single site (electro)catalysts. Moreover, we find that inappropriate computational methodologies may lead to the right predictions compared to experiment, but for the wrong reasons. This talk will present a broader overview of single-site ORR catalysis and summarize multiscale strategies for describing aqueous phase reactions.