Catalytic Conversion of CO and H₂ into Hydrocarbons on the Cobalt Co(111) Surface: Implications for the Fischer–Tropsch Process

The Fischer–Tropsch (FT) process consists of the reaction a synthesis gas (syngas) mixture containing carbon monoxide (CO) and hydrogen (H2), which are polymerized into liquid hydrocarbon chains, often using cobalt catalyst, although mechanistic pathway is not yet fully understood. Here, we have employed unrestricted density functional theory calculations with Hubbard Hamiltonian long-range dispersion corrections [DFT+U?D3?(BJ)] to investigate syngas selectivity toward hydrocarbons formed on Co(111) surface. single CO dissociated H2 molecules prefer adsorb at two different types trigonal surface sites, discuss how interatomic distances, fundamental vibrational modes, charge transfers, surface-free energies, work functions modified by adsorbates. coadsorption in close proximity provides enough energy for system cross saddle points minimum (MEP), leading catalytic hydrogenolysis C–O bond. adsorbed CO, alongside intermediates CH OH, further stabilized when ratio equilibrium coverage (C) CH/CCO,CH,OH > 6:1 under temperature conditions required FT process. We propose several pathways account formation ethane (C2H6), as model long-chain hydrocarbons, well methane (CH4) an undesirable product. MEPs these processes show that coupling C–C bond followed hydrogenation most favorable process, takes precedence over production CH4. termination suggests water (H2O) remains weakly physisorbed surface, allowing reutilization its site. simulated frequencies scanning tunneling microscopy images surface-bound agreement available experimental data. Our findings important interpretation elementary steps