Iridium-carbon monoxide adsorption

Whereas determination of chemisorption isotherms, e.g., of hydrogen on metals, is a means for calculating the size of the metallic surface area, our results clearly demonstrate that IR studies on the adsorption of nitrogen and carbon monoxide can give valuable information about the structure of the metal surface. The adsorption of nitrogen enables us to determine the number of B5 sites per unit of metal surface area, not only on nickel, but also on palladium, platinum, and iridium. Once the number of B5 sites is known, it is possible to look for other phenomena that require the presence of these sites. One has already been found, viz, the dissociative chemisorption of carbon dioxide on nickel. 

The surface areas of the iridium and palladium catalysts were determined by chemisorption of hydrogen and carbon monoxide, respectively, the monolayer volume being determined from an adsorption isotherm taken at 20°C. 

Al-Ammar AS, Webb G (1978) Hydrogenation of acetylene over supported metal catalysts Part 1 - Adsorption of [ C] Acetylene and [ C] ethylene on silica supported rhodium, iridium and palladium and alumina supported palladium. J Chem Soc Earaday Trans 74 195 Al-Ammar AS, Webb G (1979) Hydrogenation of acetylene over supported metal catalysts Part 3 - [ C] tracer studies of the effect of added ethylene and carbon monoxide on the reaction catalyzed by silica-supported palladium, rhodium and iridium. J Chem Soc Faraday Trans 75 1900... 

Boyle, R. W., et al.. Chemisorption of carbon monoxide on the iridium( 111) surface In-situ studies of adsorption and desorption kinetics via vibrational spectroscopy, Ind. Eng. Chem. Res.. 35(9). 2986-2992 (1996). 

V.V. Gorodetskii, W.M.H. Sachtler, G.K. Boreskov, B.E. Nieuwenhuys, Adsorption of oxygen and its reactions with carbon-monoxide and hydrogen on rhodium surfaces— comparison with platinum and iridium. Appl. Surf. Sci. 7(4), 355-371 (1981)... 

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