In recent years, the non-petroleum production of light olefins has been the research focus of Fischer-Tropsch olefin synthesis (FTO). Iron-based catalysts have attracted much attention because of their low price, high catalytic activity, and wide temperature range. In this paper, traditional modification, hydrophobic modification, and amphiphobic modification of the catalyst are summarized and analyzed. It was found that traditional modification (changing the pore size and surface pH of the catalyst) will reduce the dispersion of Fe, change the active center of the catalyst, and improve the selectivity of light olefins (for example, SiO2: 32%). However, compared with functional methods, these traditional methods lead to poor stability and high carbon dioxide selectivity (for example, SiO2: 34%). Hydrophobic modification can inhibit the adsorption and retention of water molecules on the catalyst and reduce the local water pressure near the iron species in the nuclear layer, thus inhibiting the further formation of CO2 (for example, SiO2: 5%) of the WGSR. Amphiphobic modification can not only inhibit the WGSR, but also reduce the steric hindrance of the catalyst, increase the diffusion rate of olefins, and inhibit the reabsorption of olefins. Follow-up research should focus on these issues.
Keywords: Fischer–Tropsch to olefins; carbon material; hydrophobic modification; iron-based catalyst; metallic oxide; molecular sieve.