PATENT

3459. ----- [STANDARD OIL CO.]  Catalyst for Fishcher-Tropsch Synthesis.  British Patent 641,261, Aug. 9, 1950.  Chem. Abs., vol. 44, 1950, p. 11067.

Catalyst is prepared by intimately combining Fe or an Fe oxide and 0.2-20% by weight of an alkali-metal ferrate (I). based on the weight of the Fe oxide; and subsequently bringing the mixture into contact with a reducing gas at a temperature of 371°-871°.  Heating the catalyst mixture in an oxidizing atmosphere is a desirable operation before the heating in the reducing atmosphere.  The Fe oxide constituent may be ferro-ferric oxide, or a- or g-Fe₂O₃.  K₂FeO₄ or Na₂FeO₄ are eminently suitable ferrates.  The ferrate may be formed by adding an oxidizing agent such as Br to a mixture of Fe(OH)₃ and an alkali-metal hydroxide.  This mixture is then added to the Fe oxide.  The compounds are intimately mixed and the product dried before heating in air.  An alternate method for preparation of the ferrate is ignition of finely divided Fe and an alkali-metal nitrate.  The product is combined with the proper amount of Fe or Fe oxide and is treated in the usual way.  While the (I) is preferably employed in purified form, the presence of minor proportions of relatively inactive contaminants is not detrimental.  An analysis of a satisfactory ferrate is K₂FeO₄ 75, KBr 20, KBrO₃ 5%.  This ferrate was employed in a catalyst composition that consisted of ferrate 5 and ferro-ferric oxide 95 parts by weight.  Desirable conditions for use of the catalyst in promoting reaction of a mixture of H₂ and CO are a temperature of 232°-357°, pressure 100-500 p. s. i. g., H₂:CO present in a ratio of 2:1 to 1:1, and feed rate of 100-1,500 vol. feed per vol. catalyst per hr.