关键词: 草酸亚铁, 制备方法, 费托合成, 催化剂, 活性, 合成气, 铁前体

Abstract:

Ferrous oxalate was used as a novel iron precursor to prepare the iron-based catalysts for Fischer-Tropsch synthesis, and the effects of four preparation methods (cocurrent co-precipitation, positive co-precipitation, precipitation-impregnation K, precipitation-impregnation K, SiO₂) on the crystal structure, physicochemical properties and catalytic properties of the catalysts were investigated. It was found that the preparation method significantly affected the crystal structure and texture properties of the catalyst. The catalyst prepared by co-precipitation had the best crystallinity and reducibility, and the promoter and the active phase was better united, so it exhibited the best activity and stability, and the conversion of CO reached 96.2%. It was also found that the catalyst prepared by the cocurrent co-precipitation method showed higher hydrocarbon product yield and C₂—C₄ olefin selectivity. The carbon number analysis showed that the content of the gasoline components in the liquid phase product obtained by the cocurrent co-precipitation method was as high as 85.8%, and that of C₄—C₁₈ in the C₄₊ heavy hydrocarbon product was as high as 91.0%. The selectivity of the kerosene component in the liquid product by the positive co-precipitation is relatively high, while the liquid phase product by the precipitate-impregnated K contained high amount of diesel components.

Key words: iron(Ⅱ) oxalate, preparation methods, Fischer-Tropsch synthesis（FTS）, catalyst, reactivity, syngas, iron precursor