摘要
以苯胺和生物质来源的丙三醇为反应原料,在铁促进的Cu/SiO2-Al2O3催化剂上气相合成了3-甲基吲哚,采用X射线光电子能谱、氢气程序升温还原(H2-TPR)、X射线衍射、透射电子显微镜、电感耦合等离子体发射光谱(ICP)、氨程序升温脱附(NH3-TPD)以及热重(TG)分析等技术对催化剂进行了表征。结果表明,向Cu/SiO2-Al2O3催化剂加入铁助剂不仅能明显提高催化剂的活性和选择性,而且能大大改善催化剂的稳定性。在Cu-Fe/SiO2-Al2O3催化剂上,反应3 h,3-甲基吲哚收率能够达到48%,而且催化剂经过再生可以重复使用,即使反应43 h,其产物收率也没有明显的降低。各种表征表明,向Cu/SiO2-Al2O3加入铁助剂能增强铜和载体之间的相互作用,由此大大提高了铜粒子在载体表面的分散度,并且有效减少了反应过程中铜组分的流失;此外,铁助剂还能显著减少催化剂的中强酸中心数,增加弱酸中心数,从而提高3-甲基吲哚的选择性,并且抑制了积炭的形成。
3-Methylindole was synthesized by vapor-phase method from aniline and biomass-derived glycerol over Fe promoted Cu/SiO2-Al2O3 catalyst. The catalysts were characterized by X-ray photoelectron spectroscopy （ XPS）, H2 temperature-programmed-reduction （ H2-TPR）, X ray diffraction （ XRD）, transmission electron microscopy （ TEM ）, inductively coupled plasma （ ICP ） emission spectroscopy, temperature-programmed- desorption of ammonia （ NH3-TPD） and thermogravimetric （TG） analysis techniques. The results indicated that the addition of Fe to Cu/SiO2-Al2O3 could not only increase the activity and selectivity clearly, but also improve the stability of the catalyst remarkably. Over Cu-Fe/SiO2-Al2O3, the yield of 3-methylindole reached 48% after three hours reaction and the catalyst could be reused by regeneration without obvious loss of the yield even after 43 h reaction. The characterizations revealed that the addition of Fe to Cu/SiO2-AI2 03 could reinforce the interaction between copper and the support, which greatly improved the dispersion of Cu particles on the surface of the support and efficiently decreased the loss of copper component during the reaction. Furthermore, Fe promoter could decrease the amount of middle-strong acid sites remarkably and increase the amount of the weak acid sites of the catalyst, which was propitious to the high selectivity of 3-methylindole and inhibited the formation of the coke. Keywords Cu/SiO2-Al2O3, iron promoter, methylindole, glycerol, aniline
出处
《应用化学》
CAS
CSCD
北大核心
2013年第10期1156-1162,共7页
Chinese Journal of Applied Chemistry
基金
国家自然科学基金(21173110)资助项目
