氧化镁助剂对一步法合成吲哚的Cu/SiO_2催化剂性能影响的研究

Study of the Effect of MgO Promorer on the Performance of Cu/SiO_2 Catalyst for the Direct Synthesis of Indole via One-Step Method

采用分步等体积浸渍法制备了Cu/S iO2-MgO催化剂,并将其用于一步法合成吲哚的反应.结果表明,当Cu/S iO2-MgO催化剂中含摩尔比0.25%铜担载量的MgO助剂时,焙烧温度为500℃,并在150℃下经混合气还原后,其催化性能最佳,吲哚的收率可达96%;当Cu/S iO2-MgO催化剂中的晶体达到一定结晶度时,其选择性很高,铜晶体的结晶度过高或过低都会导致副产物增多,吲哚的选择性降低.同时,加入氧化镁助剂能提高催化剂的稳定性.

In this paper,the Cu/SiO2 Catalyst for the direct synthesis of indole from aniline and ethylene glycol was prepared by impregnation. When n （Cu）/m（MgO） = 0.25mol% and its precursor was calcined at 500℃ and reduced in the mixture of hydrogen and nitrogen at 150℃ ,the indole yield could reach 96% ,which is much higher than that of Cu/SiO2 Catalyst. The results of XRD showed that the selectivity of Cu/SiO2 Catalyst was very high when the crystallinity of copper reached a definite value . Too high or too low copper Crystallinity could result in more by - products and less selectivity for Indole . Simultaneously, when adding MgO Promorer , the catalyst exhibited very high stability.