title: CHx hydrogenation on Co(0001): a density functional theory study.
abstract: Hydrogenation is an important process in the Fischer-Tropsch synthesis. In this work, all the elementary steps of the hydrogenation from C to CH4 are studied on both flat and stepped Co(0001) using density functional theory (DFT). We found that (i) CH3 hydrogenation (CH3+H-->CH4) is the most difficult one among all the elementary reactions on both surfaces, possessing barriers of around 1.0 eV; (ii) the other elementary reactions have the barriers below 0.9 eV on the flat and stepped surfaces; (iii) CH2 is the least stable species among all the CHx(x=1-3) species on both surfaces; and (iv) surface restructuring may have little effect on the CHx(x=0-3) hydrogenation. The barriers of each elementary step on both flat and stepped surfaces are similar and energy profiles are also similar. The reason as to why CHx hydrogenation is not structure-sensitive is also discussed.
authors.affiliation: School of Chemistry, The Queen's University of Belfast, Belfast, BT9 5AG, United Kingdom.
authors.forename: Xue-Qing
authors.initials: XQ
authors.lastname: Gong
authors.forename: R
authors.initials: R
authors.lastname: Raval
authors.forename: P
authors.initials: P
authors.lastname: Hu