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Quantification of Hydrogen Concentrations in Surface and Interface Layers and Bulk Materials through Depth Profiling with Nuclear Reaction Analysis
Published on: March 29, 2016
Hydrogen adsorption on Pd-containing Au(111) bimetallic surfaces
Sudha Venkatachalam1, Timo Jacob
1Institut für Elektrochemie, Universität Ulm, Ulm, D-89069, Germany.
Physical Chemistry Chemical Physics : PCCP
|April 17, 2009
Summary
Palladium (Pd) on gold (Au)(111) surfaces show unique hydrogen adsorption behaviors. Hydrogen adsorption stabilizes surface Pd trimers, enabling hydrogen splitting on Pd-Au surfaces.
Area of Science:
- Surface Science
- Computational Materials Science
- Catalysis
Background:
- Understanding bimetallic surface properties is crucial for catalysis.
- Gold (Au)(111) surfaces are being explored for catalytic applications.
- Palladium (Pd) is a key component in many catalytic processes.
Purpose of the Study:
- Investigate Pd configurations on Au(111) surfaces.
- Determine the stability of Pd monomers, dimers, and trimers.
- Analyze the influence of Pd on hydrogen adsorption and splitting.
Main Methods:
- Density Functional Theory (DFT) calculations were employed.
- Simulations focused on Pd substituents within a Au(111)-(3x3) unit cell.
- Analyzed Pd atom configurations in surface and subsurface layers.
Main Results:
- Prior to hydrogen adsorption, Pd monomers are favored in subsurface positions.
- Atomic hydrogen adsorption stabilizes surface Pd trimers over dimers and monomers.
- Pd substitution on Au(111) significantly enhances hydrogen adsorption energy, enabling splitting.
Conclusions:
- Pd-Au(111) bimetallic surfaces exhibit tunable stability based on Pd cluster size and location.
- Hydrogen adsorption dramatically alters the preferred Pd configuration on the Au(111) surface.
- Pd-substituted Au(111) surfaces demonstrate potential for catalytic hydrogen activation.
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