Stabilization of ε-iron carbide as high-temperature catalyst under realistic Fischer–Tropsch synthesis conditions
Shuai Lyu, Li Wang, Zhe Li, Shukun Yin, Jie Chen, Yuhua Zhang, Jinlin Li, Ye Wang
Abstract
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 2 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 2 C nanocrystals by confining them into graphene layers and obtain an iron-time yield of 1258 μmol CO g Fe −1 s −1 under realistic FT synthesis conditions, one order of magnitude higher than that of the conventional carbon-supported Fe catalyst. The ε-Fe 2 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 2 C by carburization of α-Fe precursor through interfacial interactions of ε-Fe 2 C@graphene. This work provides a promising strategy to design highly active and stable Fe-based FT catalysts.