Crystal phase and performance in unsupported Fe-Mn catalysts for fischer-tropsch synthesis

摘要

α-(Fe_1-yMn_y)_2O_3, γ-(Mn,Fe)_3O_4 and β-(Mn,FE)_2O_3 are formed when Fe-Mn catalyst precursors are calcined. While (Fe_1-xMn_x)_3O_4, (Mn, Fe)_3O_4, Fe_1-zMn_z,O, (Mn, Fe)O and Fe~0 are formed when these calcined Precursors are reduced in hydrogen. When exposed to syngas, these reduced Precursors vary with the redox environment form Fe~0 to iron carbides, Fe_1-zMn_zO, and finally to (Fe_1-xMn_x)_3O_4.