Atomic and Polymeric Carbon on Co(0001): Surface Reconstruction, Graphene Formation, and Catalyst Poisoning

• DOI: 10.1021/jp301706q
• Publication Date: 2012-05-07T09:46:15Z
• Authors: Cornelis J. Wests...; Ali C. Kızılkaya; Erwin T. R. Rossen; Martinus W. G. M....; Ionel M. Ciobîcă; Abdool M. Saib; J. W. (Hans) Niem...
• Keywords: Atomic carbon; Carbon fibers; Acetylene; Carbide-derived carbon

Atomic carbon on Co(0001), deposited by ethylene decomposition, forms islands with a (√3 × √3)R30° structure at low C coverage (∼0.2 ML), whereas high (0.5 ML, saturation) induces reconstruction of the cobalt surface. weakens adsorption CO and H2, but even saturated atomic layer does not block surface for adsorption. Carbon–carbon coupling, i.e., polymeric formation, was observed temperatures ≤630 K close-packed Polymeric carbon, in form small graphene islands, terraces after heating an acetylene-saturated Graphene also upon covered which dosed temperature. In this case, step edges act as nucleation point while their growth proceeds via addition C2Hx species. both cases, hydrogenated rather than are key precursors growth. covers surface, thereby inhibiting hydrogen completely. The described formation mechanism is seen relevant, temperature route to detrimental that would deactivate FT catalyst. more reactive graphene, it oxidized lower graphene. formed relatively poor structural quality contain (islands of) encapsulated atoms.