Adsorption of thiols on the Pd(111) surface: a first principles study

Area of Science:

• Surface Science
• Computational Chemistry
• Materials Science

Background:

• Understanding thiol adsorption on metal surfaces is crucial for catalysis and materials science.
• Palladium (Pd) is a key catalyst, and its interaction with sulfur-containing molecules is of significant interest.

Purpose of the Study:

• To investigate the adsorption behavior of different thiols on the Palladium (Pd)(111) surface.
• To elucidate the factors governing the distinct adsorption mechanisms of methane thiol and thiophene 2-thiol.

Main Methods:

• Utilizing density functional theory (DFT) formalism for theoretical calculations.
• Modeling adsorption using methane thiol and thiophene 2-thiol (TSH) as representative adsorbates.
• Analyzing the electronic structure via partial density of states (PDOS) calculations.

Main Results:

• Methane thiol exhibited spontaneous dissociative chemisorption on the Pd(111) surface.
• Thiophene 2-thiol (TSH) adsorption did not involve S-H bond cleavage, resulting in weak interaction (physisorption).
• Differences in adsorption were attributed to the electronic environment of the sulfur atom.

Conclusions:

• The adsorption mechanism of thiols on Pd(111) is highly dependent on the molecule's electronic structure.
• DFT calculations provide insights into the chemical bonding and adsorption energies at the metal-molecule interface.
• The study highlights the importance of electronic factors in determining thiol-surface interactions.