Atomistic modeling of electrocatalysis: Are we there yet?

Electrified interfaces play a prime role in energy technologies, from batteries and capacitors to heterogeneous electrocatalysis. The atomistic understanding and modeling of these interfaces is challenging due to the structural complexity and the presence of the electrochemical potential. Including the potential explicitly in the quantum mechanical simulations is equivalent to simulating systems with a surface charge. For realistic relationships between the potential and the surface charge (i.e., the capacity), the solvent and counter charge need to be considered. The solvent and electrolyte description are limited by the computational power: either molecules or ions are included explicitly or implicit solvent and electrolyte descriptions are adopted. The first option is limited by the phase-space sampling that is at least 10 times too small to reach convergence, while the second is missing a realistic structuring of the interface. Both approaches suffer from a lack of validation against directly comparable experimental data. Furthermore, the limitations of density functional theory in terms of accuracy are critical for these metal/liquid interfaces. Nevertheless, the atomistic insight in electrocatalytic interfaces allows insights with unprecedented details. The joint theoretical and experimental efforts to design non-noble hydrogen evolution catalysts are discussed as an example for the success of theory to spur and accelerate experimental discoveries. This article is categorized under: Structure and Mechanism > Reaction Mechanisms and Catalysis Electronic Structure Theory > Density Functional Theory

Automated summary

Electrified interfaces play a crucial role in energy technologies, but understanding and modeling them at an atomistic level is challenging due to their structural complexity and the presence of electrochemical potential. Realistic relationships between potential and surface charge require consideration of solvent and counter charge. However, the descriptions of solvent and electrolyte are limited by computational power, leading to validation issues in both explicit and implicit methods.