Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433, China.
Key Laboratory of Nuclear Analysis Techniques, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China.
Nat Commun. 2014 Dec 12;5:5783. doi: 10.1038/ncomms6783.
ε-Iron carbide has been predicted to be promising for low-temperature Fischer-Tropsch synthesis (LTFTS) targeting liquid fuel production. However, directional carbidation of metallic iron to ε-iron carbide is challenging due to kinetic hindrance. Here we show how rapidly quenched skeletal iron featuring nanocrystalline dimensions, low coordination number and an expanded lattice may solve this problem. We find that the carbidation of rapidly quenched skeletal iron occurs readily in situ during LTFTS at 423-473 K, giving an ε-iron carbide-dominant catalyst that exhibits superior activity to literature iron and cobalt catalysts, and comparable to more expensive noble ruthenium catalyst, coupled with high selectivity to liquid fuels and robustness without the aid of electronic or structural promoters. This finding may permit the development of an advanced energy-efficient and clean fuel-oriented FTS process on the basis of a cost-effective iron catalyst.
ε-碳化铁有望成为一种用于低温费托合成（LTFTS）以生产液体燃料的有前途的催化剂。然而，由于动力学障碍，金属铁的定向碳化生成ε-碳化铁具有挑战性。在这里，我们展示了具有纳米晶尺寸、低配位数和扩展晶格的快速淬火骨架铁如何解决这个问题。我们发现，快速淬火骨架铁在 423-473 K 的低温费托合成过程中可以很容易地原位进行碳化，得到一种以ε-碳化铁为主的催化剂，其活性优于文献中的铁和钴催化剂，与更昂贵的贵金属钌催化剂相当，同时具有较高的液体燃料选择性和稳定性，无需电子或结构促进剂的帮助。这一发现可能使基于成本效益高的铁催化剂开发出一种先进的节能、清洁的燃料导向的 FTS 工艺成为可能。
