Quantifying the origin of inter-adsorbate interactions on reactive surfaces for catalyst screening and design

Area of Science:

• Surface Science
• Computational Chemistry
• Materials Science

Background:

• Adsorption energy is crucial for heterogeneous catalyst design and screening.
• Current methods often neglect adsorbate-adsorbate interactions, impacting accuracy under reaction conditions.
• Understanding these interactions is key to modeling realistic catalytic surfaces and predicting performance.

Purpose of the Study:

• To develop and apply a method for quantitatively resolving inter-adsorbate interactions.
• To identify the physical mechanisms behind these interactions (Coulombic, steric, surface-mediated).
• To assess the impact of these interactions on adsorption energies and their dependence on surface strain.

Main Methods:

• Combining density functional theory (DFT) and cluster-expansion calculations.
• Calculating coverage-dependent adsorption energies.
• Implementing the approach on a model FeS2(100) surface with H2S adsorption.

Main Results:

• Inter-adsorbate interactions significantly affect H2S adsorption energy on FeS2(100) (up to 0.55 eV).
• Repulsive interactions are primarily driven by adsorbate-induced electronic structure changes.
• Interactions show strong strain dependence, being three times stronger under compressive than tensile strain.

Conclusions:

• Coverage-dependent adsorption energies are essential for accurate catalyst screening, especially for strained systems.
• Neglecting inter-adsorbate interactions can lead to significant errors in predicting catalytic activity.
• The developed method provides a pathway to more realistic modeling of catalytic surfaces.