Investigating methanol decomposition at low temperatures on polycrystalline Pt using near ambient pressure XPS (NAP-XPS)

Abstract

In this work, methanol was frozen on the surface of polycrystalline Pt and the decomposition of methanol was monitored from its frozen state to 195 K. This works shows that methanol spontaneously decomposes to CO on Pt even at 160 K. CO was observed to adsorb onto the top and bridge site of Pt based on the C 1s and O 1s binding energy assignment from the NAP-XPS measurement. At low temperatures, CO is preferred to bind onto the top site with a bridge to top coverage ratio of 0.4, while CO is found to be predominantly on the bridge site at room temperature, with a CO bridge to top ratio of 4. The difference in the energy of the CO binding sites were found to be 6.4 (±1.0) kJ/mol, which is in good agreement with literature.