Construction of honeycomb-like hematite superstructure on Fe foam and their application in Fischer–Tropsch synthesis

A three-dimensional (3D) honeycomb-like hematite superstructure was successfully fabricated on 100 pixel per inch (ppi) Fe foam scaffold via a straightforward hydrothermal approach. Influencing factors including the reaction temperature, time and the dosage of precipitant were systematically studied. A self-assembly growth mechanism was proposed based on the results of hydrothermal reaction. The powder catalyst in the form of zero-dimensional (0D) hematite nanoparticles acted as a reference sample was also synthesized at the same reaction conditions without Fe foam substrate. The honeycomb-like hematite structure exhibited a higher CO conversion and lower methane selectivity than the traditional powder catalyst for Fischer–Tropsch synthesis (FTS). These enhancements can be mainly attributed to its distinctive structure with high specific surface area, large Fe₃O₄ content, promoted reducibility and uniform particle size distribution, as well as effective diffusion of feed gas and products.