抄録
Adsorption and reaction of NO and CO on Ir(111) and Rh(111) were investigated by infrared reflection absorption spectroscopy (IRAS), and temperature programmed desorption (TPD). Two NO adsorption states, indicative of hollow and atop sites, were present on Ir(111). Only NO adsorbed on hollow sites dissociated to Na and Oa. Na desorbed as N2 by recombination of Na and by a disproportionation reaction between atop-NO and Na. Preadsorbed CO inhibited atop-NO, whereas hollow-NO was not affected. Adsorbed CO reacted with Oa and desorbed as CO2. NO adsorbed on the fcc-hollow, atop, and hcp-hollow sites in that order over Rh(111). The hcp-NO was inhibited by preadsorbed atop-CO, and fcc-NO and atop-NO were inhibited by CO preadsorbed on each type of the sites, indicating that NO and CO competitively adsorbed on Rh(111). From coadsorbed Rh(111) surface, N2 was produced by fcc-NO dissociation, and CO2 was formed by reaction of adsorbed CO with Oa from dissociated fcc-NO.
