Adsorption and electro-oxidation of carbon monoxide, methanol, ethanol and formic acid on osmium electrodeposited on glassy carbon

The activity of Os electrodeposited on glassy carbon (Os/GC) for the electro-oxidation of carbon monoxide, methanol, ethanol and formic acid has been studied. CO chemisorbed on Os/GC in its linear (on-top) form, as determined by in situ Fourier-transform infrared spectroscopy (FTIRS). The typical reflectance increase produced by the chemisorption of CO on thin metal films electrodeposited on glassy carbon was observed. Dissociative chemisorption of the above C1 organic compounds led to linearly chemisorbed CO. The electrolyte electroreflectance spectrum of Os/GC in CO-saturated 1 M HClO4 showed the same maximum at 270 nm already reported for Ru, Rh, Pd, Pt and Au. This maximum was assigned to an electronic transition from the Fermi level of the metal to the antibonding 2π* level of chemisorbed CO.