Based on the Fe/C ultrafine particle obtained by means of laser pyrolysis method, a series of Fe-C-Mn ultrafine particle catalysts for F-T synthesis were prepared by adding certain amounts of Mn organic compounds to t...Based on the Fe/C ultrafine particle obtained by means of laser pyrolysis method, a series of Fe-C-Mn ultrafine particle catalysts for F-T synthesis 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, Fe3Cand (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 FT synthesis and the presence of α-Fe, FexCy and (Fe, Mn)O, thus supporting the belief that these are the active phases.展开更多
Studies on ultrafine particle catalyst have attracted many researchers' attention by its large surface area,higher activity and selectivity.Based on the mechanism of α-Fe and Fe_xC_y as the catalytical active spe...Studies on ultrafine particle catalyst have attracted many researchers' attention by its large surface area,higher activity and selectivity.Based on the mechanism of α-Fe and Fe_xC_y as the catalytical active 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 was characterazed by means of XRD,electronic diffraction and TEM.It shows that the crystlline grain size is in a range of 1-4nm and composed of Fe_3C and α-Fe.It has been found that the ultrafine particle iron-carbonide catalyst exhibited much higher activity and selectivity to light olefins.At the standard atmosphere and 380℃ reaction temperature,the conversion of CO reached a maximum of 80%.展开更多
文摘Based on the Fe/C ultrafine particle obtained by means of laser pyrolysis method, a series of Fe-C-Mn ultrafine particle catalysts for F-T synthesis 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, Fe3Cand (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 FT synthesis and the presence of α-Fe, FexCy and (Fe, Mn)O, thus supporting the belief that these are the active phases.
基金The project was supported by the National Natural Science Foundation of China.
文摘Studies on ultrafine particle catalyst have attracted many researchers' attention by its large surface area,higher activity and selectivity.Based on the mechanism of α-Fe and Fe_xC_y as the catalytical active 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 was characterazed by means of XRD,electronic diffraction and TEM.It shows that the crystlline grain size is in a range of 1-4nm and composed of Fe_3C and α-Fe.It has been found that the ultrafine particle iron-carbonide catalyst exhibited much higher activity and selectivity to light olefins.At the standard atmosphere and 380℃ reaction temperature,the conversion of CO reached a maximum of 80%.
