Encapsulating Fischer-Tropsch synthesis catalyst with porous graphite-carbon enables ultrahigh activity for syngas to α-olefins.

Directly converting syngas to α-olefins via the Fischer-Tropsch synthesis reaction serves as a competitive alternative to the traditional petroleum route, which has attracted much recent attention. However, achieving high catalytic activity over the iron-based catalyst remains a grand challenge, due to the easy oxidation of the iron carbides active phase by the water produced during reaction. Herein, we present a porous graphite-carbon encapsulated iron-based catalyst, in which the iron carbides remain stable even under harsh reaction conditions of high CO conversion or high reaction temperature. Due to the excellent anti-oxidation ability of active phase, an ultrahigh activity for producing C 4+ α-olefins of 11.35 g·g cat −1·h−1 can be obtained. This work provides a promising strategy to develop iron-based Fischer-Tropsch synthesis catalysts with high catalytic activity and stability by rationally stabilizing iron carbides. [Display omitted] • A strategy to stabilize iron carbides during syngas to α-olefins was proposed. • Porous graphite-carbon encapsulated pure iron carbides was successfully prepared. • The rigid graphite-carbon protected iron carbides from oxidation by water. • Ultrahigh activity for producing C 4+ α-olefins of 11.35 g·g cat −1·h−1 was achieved. [ABSTRACT FROM AUTHOR]