铁酸镁系列超微粒子催化剂的氧化脱氢反应行为乙苯和环己烷的氧化脱氢反应

采用四种不同的方法制备了系列铁酸铁超微粒子催化剂，考察了其对乙苯和环己烷的氧化脱氢反应性能．结果表明，（Ｄ）样品具有最佳的乙苯氧化脱氢反应活性：４００℃，Ｏ２／Ｃ６Ｈ５Ｃ２Ｈ５（ｍｏｌ）＝３．０时，乙苯转化率为５０％，苯乙烯选择性为８０％，苯乙烯单收达４０％．催化剂对乙苯氧化脱氢反应的活性随样品的粒径变小而提高，对环己烷氧化脱氢反应则恰好相反，即活性随粒径变小而降低．这种差别归因于反应物分子结构与催化剂表面原子配位结构的匹配作用．ＥＳＲ结果对比表明，粒径小的粒子的原子配位结构对称性较低．

CATALYTIC BEHAVIOR OF ULTRAFINE MAGNESIUM FERRITES FOR OXYDEHYDROGENATION OF ETHYLBENZENE AND CYCLOHEXANE

Four kinds of ultrafine magnesium ferrite were prepared. And their performances for oxydehydrogenation of ethylbenzene were investigated in detail. It was found that the yield of styrene reached 40% over the optimum sample at 400C. Meanwhile, the relation was also revealed that the reactivity increased with the decreasing of the particle size.However, for oxydehydrogenation of cyclohexane, the reactivity decreased with the particle size decreasing. Furtherly, ESR result suggested that the finer particle had lower symmetry of atom coordination structure. Therefore, it was concluded that the oxydehydrogenation of ethylbenzene required the catalyst with finer particles and lower symmetry of atom coordination structure as the styrene molecule had lowersymmetry.