The influence of hydrogen on the aggregation of amino-methylidyne on Pt(111)

• Published in: Surface science 1997-06, Vol.381 (1), p.65-76
• Main Authors: Trenary, M, Celio, H, Mills, P, Jentz, D
• Format: Article
• Language: English
• ISSN: 0039-6028

The coadsorption of aminomethylidyne (CNH sub 2 ) and hydrogen on Pt(111) has been studied with reflection absorption infrared spectroscopy (RAIRS). Previous work has shown that when a clean Pt(111) surface is exposed to HCN at temperatures of 240-350K, the HCN reacts to produce the CNH sub 2 species along with adsorbed CN. The IR spectra at intermediate CNH sub 2 coverages show that three different forms of the CNH sub 2 species are present on the surface: form 1 are isolated CNH sub 2 monomers, form 2 are CNH sub 2 molecules with only one of the N-H bonds participating in a hydrogen bond to neighboring molecules, and form 3 are CNH sub 2 molecules with both N-H bonds involved in hydrogen bonding. Results are presented here demonstrating that the dominant effect of coadsorbed hydrogen is to alter the relative amounts of the three forms of CNH sub 2 , rather than to increase the amount of CNH sub 2 through hydrogenation of surface CN, which occurs to only a limited extent.