摘要
3-甲基-2-丁烯醛(3-MeCal)是一种典型的α,β-不饱和醛,其C=O加氢产物3-甲基-2-丁烯醇(3-MeCol)作为重要的有机中间体,在医药、香料、农药等生产领域有着广泛的应用.我们采用沉积沉淀法制备了Co/Al2O3催化剂,将其应用于3-MeCal液相选择性加氢反应中,考察了反应温度、H2初始压力、催化剂焙烧温度和还原温度对3-MeCal选择性加氢反应的影响.发现反应温度为80℃,H2初始压力为1×106Pa下,加氢反应效果良好.通过H2-TPR与XRD表征了焙烧温度对催化剂的影响,发现适当焙烧温度能增强Co物种与载体Al2O3间作用力.焙烧温度为600℃,还原温度为550℃下制备的催化剂反应48 min后转化率为23.0%,3-MeCol选择性达到88.6%.制备的Co/Al2O3催化剂具有良好的磁性,在外磁场作用下可与液相反应体系实现高效分离,循环使用3次后,催化性能没有明显下降,表现出良好的循环使用性能.
3-Methylcrotonaldehyde （3-MeCal） is one of typical a, fl-unsaturated aldehydes. The hydrogenated product 3-methylcrotonalcohol （3-MeCol） of the C = O has a wide application in the production of perfumes, phar- maceuticals, and pesticides etc. , as an important organic intermediate. In this contribution, Co/A1203 catalysts were prepared by a deposition-precipitation method and were used in the liquid-phase selective hydrogenation of 3- MeCal to 3-MeCol. The effect of the reaction temperature, the H2 initial pressure, and the calcination and reduc- tion temperature of the catalysts were investigated. The results indicated that the hydrogenation performs well in terms of activity and selectivity for C = 0 bond at the reaction temperature of 80 ℃ and a H2 initial pressure of 1 × 106 Pa. The H2-TPR technique was employed to investigate the effect of calcination temperature on the catalysts, indicating that a proper calcination temperature could enhance the interactions between cobalt species and alumina support. On the optimized catalyst prepared with calcination at 600 ℃ and followed by reduction at 550 ℃, after 48 minutes, the conversion of 3-MeCal could reach 23.0% with the selectivity for 3-MeCol of 88.6%. Additional- ly, the prepared Co/ Co/Al2O3 ; 3-methylcrotonaldehyde ; selective hydrogenation ; magnetic catalyst catalysts exhibited excellent magnetic properties. Under a magnetic field, the catalyst powder could be easily separated from the liquid-phase reaction system. The catalysts did not show any significant degradation in the hydrogenation of 3-MeCal after three-cycle reuse, indicating the good recyclability of the pre- pared Co/Al2O3 catalysts.
出处
《分子催化》
EI
CAS
CSCD
北大核心
2012年第4期308-313,共6页
Journal of Molecular Catalysis(China)
基金
浙江省高校重大科技攻关项目(ZD2007002)
