碱土金属氧化物对丙三醇和苯胺气相合成3-甲基吲哚的Cu/SiO2-Al2O3催化剂的作用（英文）

研究了碱土金属氧化物的添加对丙三醇和苯胺气相合成3-甲基吲哚的Cu/SiO2-Al2O3催化剂性能的影响,采用X射线衍射、透射电镜、H2程序升温还原、NH3程序升温脱附以及热重-差热等技术对催化剂进行了表征.结果表明,MgO能加强活性组分和载体之间的相互作用,从而促进铜粒子在载体上的分散.另外,MgO能增加弱酸中心数,并且抑制积炭的形成,因而Cu-MgO/SiO2-Al2O3催化剂性能大大提高;而CaO,SrO或BaO的加入不利于Cu/SiO2-Al2O3催化剂上3-甲基吲哚的生成.这是由于铜粒子在载体上的分散度变差,而且在Cu-SrO/SiO2-Al2O3及Cu-BaO/SiO2-Al2O3催化剂上弱酸中心数较少.碱土金属氧化物的加入不能改变催化剂上积炭的结构.

Effect of Alkaline-Earth Metal Oxides on Cu/SiO2-Al2O3 Catalyst for Vapor-Phase Synthesis of 3-Methylindole from Glycerol and Aniline

The effect of the addition of an alkaline-earth metal oxide (MgO, CaO, SrO or BaO) to a Cu/SiO2-Al2O3 catalyst for the vapor-phase synthesis of 3-methylindole from glycerol and aniline was investigated. The catalysts were characterized by X-ray diffraction, transmission electron microscopy, H2 temperature-programmed reduction, NH3 temperature-programmed desorption, and thermogravimetric and differential thermal analysis. MgO reinforced the interaction between copper and the support, which promoted the dispersion of Cu particles. In addition, MgO increased the amount of weak acid sites and inhibited the formation of coke. As a result, the addition of MgO to Cu/SiO2-Al2O3 gave a much improved catalyst. Adding CaO, SrO or BaO to Cu/SiO2-Al2O3 deteriorated the catalysts because the dispersion of Cu particles became worse and the amounts of weak acid sites on Cu-SrO/SiO2-Al2O3 and Cu-BaO/SiO2-Al2O3 were fewer. The addition of the alkaline-earth metal oxides did not change the texture of the coke formed.