Surface-mediated self-coupling of ethanol on gold

Area of Science:

• Surface Chemistry
• Heterogeneous Catalysis
• Nanoparticle Science

Background:

• Ethanol oxidation is crucial for producing valuable carbonyl compounds.
• Understanding gold nanoparticle catalysis is key to developing efficient oxidation processes.
• Ozone exposure on Au(111) can generate reactive oxygen species and gold nanoparticles.

Purpose of the Study:

• To elucidate the reaction mechanism of ethanol transformation on Au(111) with oxygen.
• To identify key intermediates and their roles in product formation.
• To correlate surface oxygen coverage with product distribution.

Main Methods:

• Exposure of Au(111) surfaces to ozone and ethanol.
• Analysis of reaction products including acetaldehyde, ethyl acetate, and acetic acid.
• Identification of surface intermediates such as ethoxy and acetate species.

Main Results:

• Ethanol transforms into acetaldehyde, ethyl acetate, acetic acid, and ketene on Au(111).
• Ethoxy and acetate were identified as crucial reaction intermediates.
• Product distribution is highly dependent on surface oxygen coverage.

Conclusions:

• The study reveals detailed pathways for ethanol oxidation on gold surfaces.
• Ethoxy deprotonation forms acetaldehyde, further oxidation yields acetate.
• Ethyl acetate formation involves acetaldehyde coupling with ethoxy, relevant to supported gold catalysis.