2-Propanol interacting with Co3O4(001): A combined vSFS and AIMD study.

Area of Science:

• Surface Science
• Catalysis
• Computational Chemistry

Background:

• Understanding the interaction of organic molecules with metal oxide surfaces is crucial for catalysis.
• Cobalt oxide (Co3O4) is a relevant catalyst for oxidation reactions.
• The role of water in interfacial reactions is complex and requires molecular-level investigation.

Purpose of the Study:

• To investigate the molecular-level interaction of 2-propanol with the Co3O4(001) surface.
• To elucidate the pathways of catalytic oxidation involving 2-propanol under near-ambient conditions.
• To understand the influence of water on 2-propanol adsorption and reactivity.

Main Methods:

• Vibrational sum frequency spectroscopy (VSFS) for experimental surface analysis.
• Ab initio molecular dynamics simulations for theoretical insights.
• Mimicking the solution-water interface using a water film on the Co3O4(001) surface.

Main Results:

• Both experimental and theoretical methods confirm molecular adsorption of 2-propanol.
• 2-propanol does not dissociate due to its adsorption geometry, with the O-H bond oriented away from the surface.
• Co-present water competitively adsorbs, inhibits 2-propanol deprotonation, and deactivates lattice oxygen, reducing surface activity.

Conclusions:

• Water plays a multifaceted role at the interface, influencing the catalytic oxidation of 2-propanol.
• The presence of water significantly impacts the surface reactivity of Co3O4(001) towards 2-propanol.
• 2-propanol remains molecularly adsorbed until desorption at higher temperatures.