Decomposition of methanol on Au(310)

Area of Science:

• Surface science
• Catalysis
• Materials science

Background:

• Understanding methanol interactions with metal surfaces is crucial for catalysis.
• Gold surfaces exhibit varying reactivity depending on their crystallographic orientation.
• Previous studies on Au(111) and Au(110) showed limited methanol decomposition.

Purpose of the Study:

• To investigate the interaction of methanol with the Au(310) surface.
• To determine the decomposition pathways and stability of resulting species.
• To compare the reactivity of Au(310) with other gold surfaces.

Main Methods:

• X-ray photoelectron spectroscopy (XPS) for surface chemical analysis.
• Temperature programmed desorption (TPD) to study desorption kinetics and species identification.
• Controlled methanol exposure on a Au(310) single crystal surface.

Main Results:

• At 80 K, methanol forms a physisorbed condensed layer on Au(310).
• O-H bond scission occurs above 150 K, yielding adsorbed methoxy species.
• The methoxy species remains stable up to 500 K.
• Au(310) demonstrates significantly higher reactivity towards methanol decomposition compared to Au(111) and Au(110).

Conclusions:

• The Au(310) surface exhibits unique reactivity towards methanol, promoting O-H bond scission.
• The presence of specific step and terrace sites on Au(310) likely accounts for its enhanced catalytic activity.
• These findings highlight the importance of surface structure in heterogeneous catalysis.