Ultraviolet Photoemission Studies of Formaldehyde and Related Molecules Adsorbed on Ru(110).

摘要

The adsorption of formaldehyde (H2CO),hydrogen,and carbon monoxide on Ru(110) has been studied using angle-integrated ultraviolet photoemission spectroscopy (UPS) and temperature programmed desorption (TPD). The UPS spectra for low exposures of H2CO at 80 K indicate that H2CO dissociates to a substantial degree. These spectra are compared with UPS spectra for the sequential adsorption of hydrogen and CO. Whereas there are similarities between these spectra,the differences in the UPS,work function change,and TPD results are sufficient to suggest that a portion of the dissociated H2CO may exist as a surface molecular complex containing H and CO. This is apparently the first reported example,based on a UPS study,of an oxygen-containing organic molecule which dissociates upon adsorption on a metal surface at 80 K. For high exposures at 80 K,adsorption of a condensed layer of molecular H2CO is observed. (Author)