Step Effects in the Thermal Decomposition of Methanol on Pt (111).

Methanol decomposition to adsorbed CO and hydrogen on Pt(111) was observed using time-resolved high resolution electron energy loss spectroscopy. No reaction was seen at temperatures ~180K, the molecular methanol desorption temperature. Between 180 and 200K the decomposition reaction is controlled by the small amount of defects present on our carefully prepared sample. This was principally demonstrated by the fact that only 1- 2% of a monolayer of CO was formed regardless of the initial methanol coverage. A steady state reaction run between 200 and 240K, shows only a low rate of CO formation (only a few percent of a monolayer even after many Langmuirs exposure of methanol).