Self-driven microstructural evolution of Au@Pd core-shell nanoparticles for greatly enhanced catalytic performance...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Understanding microstructural changes in catalysts under electrochemical conditions is crucial for developing advanced heterogeneous catalysts.
• Direct insights into these dynamic evolutions have been limited, hindering catalyst design.

Purpose of the Study:

• To investigate the microstructural evolution of gold-palladium (Au@Pd) core-shell nanostructures during the methanol electrooxidation reaction (MOR).
• To elucidate the relationship between microstructural changes and electrocatalytic activity.

Main Methods:

• Electrochemical polarization and cyclic voltammetry were employed to study the Au@Pd core-shell nanostructures.
• Microstructural characterization techniques were utilized to analyze changes in the catalyst's shell.
• Computational methods were used to support experimental findings.

Main Results:

• The electrocatalytic activity of Au@Pd core-shell nanoparticles increased with successive MOR cycles.
• A self-driven microstructural evolution resulted in the formation of a mixed Au/Pd bimetallic shell.
• The mixed shell altered OH- and CO binding strengths and facilitated oxidative removal of carbonaceous species.

Conclusions:

• The dynamic formation of a mixed Au/Pd shell is key to enhanced electrocatalytic performance in MOR.
• Exposed Au atoms contribute to the removal of adsorbed species, improving catalyst efficiency.
• This study provides critical insights into catalyst self-evolution for improved heterogeneous catalysis.