Plasmon-Mediated Hydrogen Dissociation with Symmetry Tunability

Area of Science:

• Physical Chemistry
• Materials Science
• Quantum Mechanics

Background:

• Plasmon-mediated catalysis offers novel pathways for chemical reactions.
• Understanding atomic-scale mechanisms is crucial for optimizing photocatalytic efficiency.
• Gold nanoclusters exhibit unique plasmonic properties relevant to catalysis.

Purpose of the Study:

• To investigate the atomic-scale mechanism of plasmon-mediated H2 dissociation on gold nanoclusters.
• To elucidate the role of molecular position and structural symmetry in reaction dynamics.
• To explore the influence of plasmon decay and charge transfer on H2 dissociation.

Main Methods:

• Time-dependent density functional theory (TDDFT) calculations were employed.
• Simulations focused on the interaction between gold nanoclusters and H2 molecules.
• Analysis of electronic structure and reaction pathways under plasmonic excitation.

Main Results:

• The position of the H2 molecule relative to the gold nanocluster significantly impacts dissociation rates.
• Optimal H2 positioning within the plasmonic dimer's hot spot enhances dissociation.
• Symmetry breaking due to altered molecular position inhibits dissociation.
• Direct charge transfer from the gold cluster to H2's antibonding state is a key dissociation pathway in asymmetric structures.

Conclusions:

• Structural symmetry plays a critical role in plasmon-assisted photocatalysis at the quantum level.
• Hot spot field enhancement in plasmonic dimers is vital for efficient H2 dissociation.
• Insights gained can guide the design of advanced plasmonic catalysts.