Quantum-Chemical DFT Study of Direct and H- and C-Assisted CO Dissociation on the χ-Fe5C2 Hagg Carbide.

ABSTRACT: The first step in the Fischer-Tropsch reaction is the production of C1 monomers by the dissociation of the C-O bond. Although Fe is the active metal, it is well known that under typical reaction conditions, it changes into various carbide phases. The Hägg carbide (χ-Fe5C2) phase is usually considered as the catalytically active phase. We carried out a comprehensive DFT study of CO dissociation on various surface terminations of the Hägg carbide, selected on their specific site topology and the presence of stepped sites. Based on the reaction energetics, we identified several feasible CO dissociation pathways over the Hägg carbide. In this study, we have compared the direct CO dissociation with H- and C-assisted CO dissociation mechanisms. We demonstrated that the reaction rate for CO disso

SUBMITTER: Broos RJP 

PROVIDER: S-EPMC5949720 | biostudies-literature | 2018 May

REPOSITORIES: biostudies-literature