Initial behavior of a reduced fused-magnetite catalyst in the Fischer-Tropsch synthesis

In studies at 232 and 248/sup 0/C and 0.92 MPa, during the first 20 h on stream, both Fischer-Tropsch synthesis activity and CO consumption increased to quasi-steady-state values. The bulk catalyst, initially ..cap alpha..-Fe, was converted to a mixture of ..cap alpha..-Fe and iron carbides, as determined by Mossbauer spectroscopy. During the first few hours, methane selectivity decreased markedly while the olefin/paraffin ratio increased. No change was observed in the C/sub 2/-C/sub 8/ product distribution with time on stream.