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用~(57)Fe穆斯堡尔谱研究了炭载型复合催化剂中铁化学形态随温度的变化,及各活性组分、助剂对铁化学形态的影响;并通过ESR谱考察了复合催化剂中不同活性组分对铁在载体炭表面电子特性的影响。研究结果表明,复合催化剂中各活性组分、助剂和载体炭与铁之间存在着强相互作用。在350～650℃,载体炭可将铁从Fe_2O_3还原到Fe_3O_4、FeO、α-Fe和生成炭化铁。活性组分Cu和助剂K可改变催化剂中铁周围的电子密度,促进铁在载体炭上从高价态向低价态还原。同时还发现催化剂中Na和Cr对铁有很强的助分散作用。
The change of the chemical state of iron in the carbon supported composite catalyst with temperature and the influence of various active components and auxiliaries on the chemical speciation of iron were studied by ~ (57) Fe Mössbauer spectroscopy. Effect of different active components on the electronic properties of iron on carbon carrier. The results show that the active components in the composite catalyst, additives and carrier carbon and iron there is a strong interaction between. At 350 ~ 650 ℃, the carrier carbon can reduce iron from Fe_2O_3 to Fe_3O_4, FeO, α-Fe and form iron carbide. The active component Cu and additive K can change the electron density around the iron in the catalyst and promote the reduction of iron on the carrier carbon from the high valence state to the low valence state. At the same time, it was also found that Na and Cr in the catalyst have a strong role in helping dispersion of iron.