Wesner, D. A.; Linden, G.; Bonzel, H. P.

Applied Surface Science (1986), 26(3), 335-56 CODEN: ASUSEE; ISSN: 0169-4332. English.

A surface study was made of CO adsorption and the Fischer-Tropsch reaction on Co foils with K precoverages of 0-0.8 monolayers. XPS and AES were used to characterize the adsorbed surface species. Mol. CO 1s levels exhibited a K-dependent binding energy decrease attributed to a surface-to-mol. charge transfer enhanced by the alkali. K enhanced the amount of CO adsorbed and thermally stabilized the adsorbed mol. Surface anal. after Fischer-Tropsch reaction showed that for identical reaction conditions, clean Co shows much less deposited C than clean Fe. It also forms surface carbidic C deposits much less readily than Fe, the C deposited being predominantly graphitic. K predosing of the surfaces enhanced the amount of C deposited, attributable to its enhancement of the CO adsorption step. It also changed the nature of the C, inducing carbidic C. The reactivity of carbidic C to H on both Co and Fe was reduced by K.