| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1986: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1985: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Research Abstract |
Fischer-Tropsch (F-T) synthesis on a Fe powder catalyst, prepared by reduction of <FeI_2> with molten potassium metal in refluxing THF, produced 1-butene with quite high selectivity. The purpose of the present study is to clarify the F-T catalytic properties of the powders and to elucidate the origin of appearence of such unique catalytic properties. The results obtained are summarized as follows:
1. F-T syntheses under various conditions demonstrated that 1-butene was produced the most efficiently at 260-280゜C, at <H_2> /CO ratio of 1.5, and on Fe-Co (8:2) binary catalyst. After <H_2> -pretreatment, the unique catalytic properties of the Fe powder disappeared. Amount of KI contaminated in the Fe powder brought little effect for the F-T synthesis.
2. The Fe powder contained 1.6 wt% carbon by elemental analysis and <CH_4> , <CO_2> , CO, and <C_2H_6> were evolved by <H_2> heat-treatments. XPS analyses indicates that the Fe surface was covered with some different kinds of carbonaceous species, the main components of which were graphite and/or hydrocarbons such as ethylene. Accumulation of carbonaceous species on the original Fe powder was observed by a treatment with <H_2> /CO under similar conditions to that employed for the F-T synthesis, while little accumulation was observed for the <H_2> -pretreated Fe powder.
3. On a Fe powder prepared by Birch reduction, which contained no carbonaceous overlayers, F-T products obeyed conventional Schulz-Flory type distributions. When this Fe powder was subjected to methanol treatrment, deposition of carbon occurred. A F-T synthesis on the methanol-treated Fe powder produced <C_3> -fraction with 40 % selectivity.
These results strongly suggest that carbonaceous overlayers present on the Fe powder are connected to the appearence of the unique catalytic properties for selective production of low molecular-mass hydrocarbons.
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