Stabilization of ?-iron carbide as high-temperature catalyst under realistic Fischer-Tropsch synthesis conditions.

ABSTRACT: The development of efficient catalysts for Fischer-Tropsch (FT) synthesis, a core reaction in the utilization of non-petroleum carbon resources to supply energy and chemicals, has attracted much recent attention. ?-Iron carbide (?-Fe₂C) was proposed as the most active iron phase for FT synthesis, but this phase is generally unstable under realistic FT reaction conditions (> 523?K). Here, we succeed in stabilizing pure-phase ?-Fe₂C nanocrystals by confining them into graphene layers and obtain an iron-time yield of 1258??mol_CO g_Fe^-1s^-1 under realistic FT synthesis conditions, one order of magnitude higher than that of the conventional carbon-supported Fe catalyst. The ?-Fe₂C@graphene catalyst is stable at least for 400?h under high-temperature conditions. Density functional theory (DFT) calculations reveal the feasible formation of ?-Fe₂C by carburization of ?-Fe precursor through interfacial interactions of ?-Fe₂C@graphene. This work provides a promising strategy to design highly active and stable Fe-based FT catalysts.

SUBMITTER: Lyu S 

PROVIDER: S-EPMC7719174 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature