Stabilization of ε-iron carbide as high-temperature catalyst under realistic Fischer-Tropsch synthesis conditions.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33277482.
- Also identified by DOI 10.1038/s41467-020-20068-5 and PMC identifier 7719174.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
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. ε-Iron carbide (ε-Fe<sub>2</sub>C) 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 ε-Fe<sub>2</sub>C nanocrystals by confining them into graphene layers and obtain an iron-time yield of 1258 μmol<sub>CO</sub> g<sub>Fe</sub><sup>-1</sup>s<sup>-1</sup> under realistic FT synthesis conditions, one order of magnitude higher than that of the conventional carbon-supported Fe catalyst. The ε-Fe<sub>2</sub>C@graphene catalyst is stable at least for 400 h under high-temperature conditions. Density functional theory (DFT) calculations reveal the feasible formation of ε-Fe<sub>2</sub>C by carburization of α-Fe precursor through interfacial interactions of ε-Fe<sub>2</sub>C@graphene. This work provides a promising strategy to design highly active and stable Fe-based FT catalysts.