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常压下乙烯在Rh-Y分子筛催化剂上的氢甲酰化反应存在一定的诱导期。在反应条件下,加氢反应和氢甲酰化反应同时进行。在反应初期,含氧化合物活性的增加伴随着乙烷活性的降低,反应达到平衡的时间取决于对催化剂的预处理条件,反应前后,催化剂的颜色有明显变化(淡黄色变成红棕色):根据XPS的研究结果,新鲜催化剂与用过催化剂的Rh_3d5/2结合能为309.1和306.9eV,分别对应于铑的三价态和零价态。这预示着金属态的铑粒子可能是乙烯氢甲酰化反应的活性中心或它的前身。另外,反应条件下的红外光谱清楚地表明,催化剂的H_2还原处理在活性中心的形成过程中起着非常重要的作用。
Atmospheric pressure ethylene in the Rh-Y zeolite catalyst hydroformylation reaction there is a certain period of induction. Under the reaction conditions, the hydrogenation reaction and the hydroformylation reaction proceed simultaneously. At the beginning of the reaction, the increase of the activity of the oxygenate is accompanied by the decrease of the activity of the ethane. The time for the reaction to reach equilibrium depends on the conditions for the pretreatment of the catalyst. Before and after the reaction, the color of the catalyst changes obviously (light yellow to reddish brown) According to the results of XPS, the Rh3d5 / 2 binding energies of fresh catalyst and spent catalyst were 309.1 and 306.9eV, corresponding to the trivalent and zero valence states of rhodium respectively. This indicates that the metallic rhodium particles may be the active center of ethylene hydroformylation or its predecessor. In addition, the IR spectra of the reaction conditions clearly show that the H 2 reduction of the catalyst plays a very important role in the formation of the active center.