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用穆斯堡尔谱、程序升温还原和Cahn微量天平技术研究了Fe_2O_3/γ-Al_2O_3,Fe_2O_3-La_2O_3/γ-Al_2O_3和Fe_2O_3/La_2O_3/γ-Al_2O_3催化剂的载体与活性组分的相互作用。结果表明:用La_2O_3改性后的Fe_2O_3/La_2O_3/γ-Al_2O_3催化剂,载体与活性组分的相互作用加强,使FeO(Ⅱ)相得到稳定并难以还原为零价铁。同时改性的效果与La_2O_3的添加方式有关,对共浸催化剂Fe_2O_3-La_20_3/γ-Al_2O_3·La_2O_3可能仅起到助剂的作用。La_2O_3的添加还提高了催化剂的还原速度。
The interaction between the supported and active components of Fe_2O_3 / γ-Al_2O_3, Fe_2O_3-La_2O_3 / γ-Al_2O_3 and Fe_2O_3 / La_2O_3 / γ-Al_2O_3 catalysts was investigated by Mossbauer spectroscopy, temperature programmed reduction and Cahn microbalance. The results show that the interaction between the support and the active component is enhanced by the La_2O_3 modified Fe_2O_3 / La_2O_3 / γ-Al_2O_3 catalyst, which makes the FeO (Ⅱ) phase stable and difficult to reduce to zero valent iron. At the same time, the effect of modification is related to the addition mode of La2O3, and the co-impregnation catalyst Fe2O3-La2O3 / γ-Al2O3-La2O3 may only play an auxiliary role. The addition of La 2 O 3 also increases the reduction rate of the catalyst.