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采用Mossbauer谱学方法对Fe-Y沸石催化剂活性组成的价态、中间络合物的形成条件和水煤气变换反应进行了测试,并对Fe~+离子在Y沸石中的可能位置进行了初步理论计算。结果表明:Y沸石中的Fe~(3+)和Fe~(2+)离子均有两种以上不同的铁环境;抽空脱水时,部分Fe~(3+)被还原成Fe~(2+)并出现价态介于Fe~(3+)与Fe~(2+)之间的中间络合物,其可能模型是Fe~(3+)—O—Fe~(2+),桥连的两个铁离子之间电子云分布平均;实际反应条件下,也有类似表征过渡中间络合物的新物类出现;吸附和实际反应谱的分析指出:在有水和OH-基团存在下,CO吸附很容易使Fe~(3+)还原。
The valence states of active Fe-Y zeolite catalyst, the formation conditions of intermediate complexes and the water gas shift reaction were tested by Mossbauer spectroscopy. The possible theoretical positions of Fe ~ + ions in Y zeolites were also calculated . The results show that Fe 3+ and Fe 2+ ions in Y zeolite have two or more different iron environments. During the dehydration, part of Fe 3+ is reduced to Fe 2+, ) And the intermediate complexes with the valence state between Fe 3+ and Fe 2+ appear. The possible model is Fe 3+ O-Fe 2+, Of the two iron ions distributed electron cloud average; under the actual reaction conditions, there are also similar to the transition intermediate complexes appear new species; adsorption and the actual response spectrum analysis shows that: in the presence of water and OH- groups , CO adsorption can easily reduce Fe 3+.