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用吸附和程序升温脱附的方法,研究了不同组成铁锑氧化物催化剂上丙烯的吸附和脱附以及催化剂的再氧化。催化剂中Sb原子含量由零增加至90％时,单位表面丙烯的吸附量总的变化趋势是增加的,脱附后催化剂的再氧化吸氧量也呈现同样的规律。不同组成铁锑氧化物上丙烯氨氧化合成丙烯腈的催化活性和选择性与丙烯的吸附量无直接对应关系。丙烯程序升温脱附和对脱附产物的分析表明,不同组成的催化剂的表面氧化能力和脱附性质有明显的区别。由Mossbauer谱的分析结果可以认为锑酸铁是催化剂表面的主要提供者。根据丙烯吸附和催化反应的结果,推测选择性氧化的吸附中心可能与锑离子相关。
Adsorption and temperature-programmed desorption were used to study the adsorption and desorption of propylene and the reoxidation of the catalysts on the iron oxide antimony oxides with different compositions. When the content of Sb atom in the catalyst increases from zero to 90%, the total adsorption of propylene on the unit surface tends to increase, and the reoxidation and oxygen uptake of the catalyst after desorption also show the same rule. There is no direct correspondence between the catalytic activity and selectivity of propylene ammoxidation of acrylonitrile over propylene iron oxide with different compositions. The temperature programmed desorption of propylene and the analysis of the desorption products showed that there were obvious differences in the surface oxidation and desorption properties of the catalysts with different compositions. The results of Mossbauer spectroscopy suggest that iron antimonate is the major contributor to the catalyst surface. According to the results of propylene adsorption and catalytic reaction, it is speculated that the selective oxidation of the adsorption center may be related to antimony ions.