| 摘 要： | Studies on ultrafine particle catalyst have attracted many researchers' attention by its large surfacearea,higher activity and selectivity.Based on the mechanism of α-Fe and Fe_xC_y as the catalyticalactive species this paper reports for the first time the preparation method of Fe_3C ultrafine parti-cle catalyst,from highly dispersed amorphous Fe powder and free carbon.The Fe powder and free car-bon,prepared by laser pyrolysis technique,was then treated by washing and heating at high tempera-ture protected with N_2.The catalyst prepared under different experimental conditions wascharacterazed by means of XRD,electronic diffraction and TEM.It shows that the crystlline grain sizeis in a range of 1-4nm and composed of Fe_3C and α-Fe.It has been found that the ultrafine particleiron-carbonide catalyst exhibited much higher activity and selectivity to light olefins.At the standardatmosphere and 380℃ reaction temperature,the conversion of CO reached a maximum of 80%.
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