CO adsorption on the GaPd(1[combining macron]1[combining macron]1[combining macron]) surface: a comparative DFT study...

Area of Science:

• Surface Science
• Computational Materials Science
• Physical Chemistry

Background:

• Understanding carbon monoxide (CO) adsorption on transition metal surfaces is crucial for catalysis and materials science.
• The polar (111) surface of the intermetallic compound Gallium Palladium (GaPd) presents a unique system for studying adsorption phenomena.
• The 'CO adsorption puzzle' highlights challenges in accurately modeling CO bonding on surfaces with transition metals.

Purpose of the Study:

• To investigate carbon monoxide (CO) adsorption on the polar (111) surface of the GaPd intermetallic compound.
• To evaluate the performance of various density functional theory (DFT) functionals in describing CO adsorption on this surface.
• To identify a computational method that accurately reproduces experimental observations.

Main Methods:

• Utilized ab initio methods with an all-electron full-potential electronic structure approach.
• Calculated bulk, clean surface, and CO adsorption properties using PW-LDA, GGA-PBE, GGA-RPBE, GGA-revPBE, and HSE06 functionals.
• Compared first-principles results with existing experimental data.

Main Results:

• The choice of DFT functional significantly impacts the description of CO adsorption on the GaPd (111) surface.
• Standard functionals (LDA, PBE) provide only partial agreement with experimental findings, failing to capture the complex bonding.
• The hybrid HSE06 functional successfully reproduces experimental trends for adsorption energies, vibrational frequencies, and surface-adsorbate interactions.

Conclusions:

• The hybrid HSE06 functional is recommended for accurate theoretical studies of CO adsorption on GaPd surfaces.
• This work resolves discrepancies in previous computational studies, contributing to a better understanding of the 'CO adsorption puzzle'.
• Accurate modeling is essential for predicting and designing materials for catalytic applications involving CO.