Ethanol adsorption, decomposition and oxidation on Ir(111): A high resolution XPS study

Ethanol (C2H5OH) adsorption, decomposition and oxidation is studied on Ir(111) using high-energy resolution, fast XPS and temperature-programmed desorption. During heating of an adsorbed ethanol layer a part of the C2H5OHad desorbs molecularly, and another part remains on the surface and decomposes around 200 K; these two decomposition pathways are identified, as via acetyl (H3C-,C=O) and via COad:+ CH3ad, respectively. Acetyl and CH3ad decomposed around 300 K into CHad (and COad). CHad decomposes forming C-x and H-2 around 520 K. In the presence of O-ad an acetate intermediate is formed around 180 K, as well as a small amount of CH3ad and COad. Acetate decomposes between 400-480 K into CO2, H-2(/H2O) and CHad.