Molecular dynamics study of plasmon-mediated chemical transformations

Area of Science:

• Surface science and heterogeneous catalysis
• Photochemistry and plasmonics
• Computational chemistry and molecular dynamics

Background:

• Plasmon-mediated catalysis on metallic surfaces offers high photoelectric conversion efficiency and tunable selectivity.
• Understanding the complex interplay of light absorption, charge transfer, and energy relaxation is crucial for optimizing these processes.
• Theoretical modeling is essential for dissecting the ultrafast dynamics in plasmon-driven chemical reactions.

Purpose of the Study:

• To investigate the dynamics of plasmon excitation and energy relaxation in a model Au20-CO system.
• To elucidate the mechanisms of hot carrier generation, transfer, and CO activation.
• To provide atomistic insights into plasmon-mediated chemical transformations using non-adiabatic molecular dynamics.

Main Methods:

• Trajectory surface hopping non-adiabatic molecular dynamics simulations.
• Analysis of electronic properties and charge transfer dynamics.
• Investigation of electron-vibration coupling and C-O bond activation.

Main Results:

• Plasmon excitation of Au20-CO leads to partial charge transfer from Au20 to CO.
• Hot carriers generated after plasmon excitation exhibit bidirectional transfer between Au20 and CO.
• Non-adiabatic couplings activate the C-O stretching mode, leading to CO activation.
• An overall plasmon-mediated transformation efficiency of approximately 40% was determined.

Conclusions:

• Non-adiabatic molecular dynamics simulations provide critical dynamical and atomistic insights into plasmon-mediated catalysis.
• The study highlights the importance of hot carrier dynamics and electron-vibration coupling in CO activation.
• The findings contribute to the fundamental understanding of light-driven chemical transformations on metallic nanostructures.