Interfacial electric fields catalyze Ullmann coupling reactions on gold surfaces.

Area of Science:

• Surface science
• Heterogeneous catalysis
• Physical chemistry

Background:

• Interfacial electric fields play a crucial role in heterogeneous catalysis.
• Understanding these fields is key to optimizing catalytic processes.

Purpose of the Study:

• To investigate the role of electric fields in Ullmann coupling reactions.
• To explore the influence of surface roughness and solvent polarity on catalysis.
• To develop a method for real-time probing of interfacial catalysis.

Main Methods:

• In situ monitoring using scanning tunneling microscope-based break junction (STM-BJ).
• Ex situ analysis via mass spectrometry and fluorescence spectroscopy.
• Density functional theory (DFT) calculations for theoretical support.

Main Results:

• Ullmann coupling of aryl iodides was observed exclusively on rough gold surfaces.
• The reaction's dependence on polar solvents highlights the significance of interfacial electric fields.
• DFT calculations confirmed the impact of surface roughness and local electric fields.

Conclusions:

• Interfacial electric fields are critical for Ullmann coupling on rough gold surfaces.
• This work provides a novel approach to study interfacial catalysis in real time.
• The findings contribute to a deeper understanding of electric field-driven catalytic mechanisms.