摘要
无机介孔氧化硅材料具有规整的孔道结构、连续可调的孔径、良好的稳定性等优点,可作为催化反应的微囊反应器。今以无机介孔二氧化硅微球为微囊反应器,利用"ship-in-a-bottle"策略,将均相催化剂封装在介孔SiO2微球中,采用SEM、BET、TEM、FT-IR等手段进行表征,并应用在苯乙酮的不对称氢转移反应中。在60℃下反应6h,苯乙酮转化率和苯乙醇的对映体选择性最高分别达到52.4%和95.5%,且重复使用5次后,催化剂仍保持较高活性。以甲酸钠为氢源,考察了反应温度、反应时间、反应物的加入量对底物转化率和产物对映体选择性的影响。研究结果表明,将均相铑催化剂封装在二氧化硅微囊反应器中,在获得高转化率和对映体选择性的同时,可以提高催化剂的重复利用率,降低生产成本,符合绿色化学的要求。
Inorganic mesoporous silica can be used as a microcapsule reactor for its regular spherical structure, slits pore structure and good stability. Rhodium catalysts were synthesized in mesoporous silica through a ＂ship-in-a-bottle＂ strategy and used for asymmetric transfer hydrogenation of acetophenone. The structure of the microcapsule reactor was characterized through BET, XRD, FT-IR and TEM. Effects of reaction temperature, reaction time, reactant amount on catalyst performance were investigated with sodium formate as the hydrogen source. Under optimum conditions of 60℃, 6 h and 0.2 m L acetophenone, the catalyst shows its highest performance of acetophenone conversion（52.4%） and enantio selectivity（95.5%） of R-α-phenethyl alcohol in asymmetric transfer hydrogenation of acetophenone. The conversion and ee value maintained after recycling for five times. The results show that the catalyst supported with mesoporous silica through ＂ship-in-a-bottle＂ strategy has good catalytic performance and can be recycled, which complies with the requirements of green chemistry.
作者
张一颖
闫宇强
曹发海
ZHANG Yi-ying;YAN Yu-qiang;CAO Fa-hai(Engineering Research Center of Large Scale Reactor Engineering and Technology of Ministry of Education,East China University of Science and Technology,Shanghai 200237,China)
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2018年第5期1082-1089,共8页
Journal of Chemical Engineering of Chinese Universities
关键词
二氧化硅
微囊反应器
瓶中存船
不对称氢转移
手性α-苯乙醇
silica
microcapsule reactor
ship-in-a-bottle
asymmetric transfer hydrogenation
chiral α-phenylethanol
