Adsorption and oxidation of glycine on Au electrode: An in situ surface-enhanced infrared study

The adsorption and oxidation of glycine on Au surface are studied by cyclic voltammetry coupled with in situ surface-enhanced infrared spectroscopy. The infrared spectra definitely indicate that glycine is adsorbed on the electrode with two oxygen atoms directing the Cα-C bond perpendicular to the surface. During glycine oxidation, cyanide is formed and oxidized to cyanate at high potentials. It is also shown that ureylene biradical species (deprotpnated urea) bonded to the surface via two nitrogen atoms is formed on oxidized Au surface. Combining experimental results reported in the literature, the mechanism of glycine electrooxidation is discussed.