A first-principles study of methanol decomposition on Pt(111)

Area of Science:

• Surface Chemistry
• Catalysis
• Computational Materials Science

Background:

• Methanol decomposition on platinum is crucial for catalysis.
• Understanding reaction intermediates and transition states is key.

Purpose of the Study:

• To investigate the mechanism of methanol decomposition on Pt(111) using Density Functional Theory.
• To determine thermochemistry and activation barriers for elementary steps.
• To identify the rate-limiting step and stable intermediates.

Main Methods:

• Periodic, self-consistent Density Functional Theory calculations.
• Analysis of elementary reaction steps and potential energy surfaces.
• Identification of stable intermediates and transition states.

Main Results:

• The O-H bond scission is the initial step, followed by sequential hydrogen abstraction.
• Hydroxyl hydrogen abstraction from methanol is the rate-limiting step.
• Carbon monoxide is a strong thermodynamic sink; intermediates like methoxy, formaldehyde, and formyl have short lifetimes.

Conclusions:

• The decomposition pathway is well-defined with hydroxyl hydrogen abstraction as the bottleneck.
• Intermediates and transition states adhere to surface coordination and bond order rules.
• This provides fundamental insights into methanol oxidation catalysis on platinum.