Comparative Study of Different Mesostructured Silica-supported Nano-iron Catalysts for Fischer–Tropsch Synthesis

Fischer-Tropsch synthesis (FTS) converts syngas into multi-carbon products, whose distribution is highly dependent on the catalyst structure. Here, nano-iron catalysts with different silica supports were prepared, and their activities and durability for Fischer-Tropsch to olefins (FTO) process were investigated. Fe/KCC-1 demonstrated the best FTO catalytic selectivity of 25.0% for C_2–4⁼ and an olefin-to-paraffin ratio of 1.68. Its open pore structure allowed primary olefins to escape quickly from the catalyst surface, lowering the probability for secondary reactions. However, its durability was lower than Fe/SBA-15 due to coke formation, pore structure collapse and Fe particle agglomeration. The thermal stability of SBA-15 resulted in its better durability, and the encapsulated Fe particles inside the cylindrical mesopores also allowed better resistance to sintering. However, the less open structure of Fe/SBA-15 led to longer residence time for the primary olefins and increased possibility for secondary reactions, causing undesired chain growth.