Abstract: Based on the Fe/Cultrafine particle obtained by means of laser pyrolysis method, a series of Fe-C-Mn ultrafine particle catalysts for F-Tsynthesis were prepared by adding certain amounts of Mn organic compounds to the Fe/C UFP. XRD and TEM tests for the obtained catalysts showed that the active phases, α-Fe, Fe₃C and (Fe,Mn)O. were directly obtained. and that the particle size was in the range of 2-4 nm. The catalysts so obtained have stable structure, long life, high activity and selectivity for light olefins, especially for propylene. Testing of the crystal structure in the process of the reaction demonstrated the carbonide mechanism of FTsynthesis and the presence of α-Fe, Fe_xC_yand (Fe, Mn)O, thus supporting the belief that these are the active phases.

Key words: F-T synthesis, Ultrafine particle, Fe-C-Mn catalyst