Thermal reactions of mercaptoethanol on Cu(1 0 0)

Reflection-absorption infrared spectroscopy (RAIRS) and temperature-programmed reaction/desorption (TPR/D) have been employed to investigate the thermal decomposition of HSCH₂CH₂OH on Cu(1 0 0) and the surface intermediates involved. The surface reactions of HSCH₂CH₂OH proceed via several stages in sequence, including production of surface intermediates of -SCH₂CH ₂OH, -SCH₂CH₂O-, and the species possibly containing >C=C=O or >C=C=S. Carbon-containing products of CH ₄, C₂H₄, and CH₃CHO evolve between 300 and 500 K and C₂H₄ is the major product. Desorption of sulfur-containing products is not observed. HSCH₂CH₂OH dissociates on Cu(1 0 0) and oxygen-precovered Cu(1 0 0) to form -SCH ₂CH₂OH at dosing temperature of 115 K. However -SCH ₂CH₂O- and the species containing >C=C=O or >C=C=S are generated at lower temperatures on oxygen-precovered Cu(1 0 0). C ₂H₄ is also the major desorption product from HSCH ₂CH₂OH on oxygen-precovered Cu(1 0 0).