奎宁-杂多酸杂化催化剂催化H_2O_2为氧源的苯羟基化反应(英文)  

Direct hydroxylation of benzene to phenol with hydrogen peroxide catalyzed by a quinine-heteropolyacid hybrid

作　　者：赵萍萍[1] 周瑜[1] 刘阳庆 王军[1] 

机构地区：[1]南京工业大学化学化工学院材料化学工程国家重点实验室,江苏南京210009

出　　处：《催化学报》2013年第11期2118-2124,共7页

基　　金：supported by the National Natural Science Foundation of China (21136005)~~

摘　　要：将奎宁与Keggin结构磷钼钒杂多酸结合制备出一种新颖的多相苯羟基化杂化催化剂,采用傅里叶变换红外光谱、紫外-可见光谱、X射线衍射、扫描电镜、热重、N2吸附-脱附和CHN元素分析等表征手段对催化剂进行了分析.结果表明,该催化剂是一种具有较高比表面积和孔体积的半无定形有机杂多酸盐.在H2O2为氧源的苯羟基化反应中,杂化催化剂引导了液-固两相催化体系,表现出较高催化活性和重复使用稳定性.催化剂中奎宁与杂多阴离子间的氢键和电子相互作用赋予了其高熔点和难溶性,而高比表面积和因奎宁而改善的杂多阴离子的氧化还原性是其获得优异催化性能的主要原因.这为多相苯羟基化反应提供了一种新的且制备便捷的基于多金属氧酸盐的高效催化剂.A new heterogeneous hybrid catalyst designed for direct hydroxylation of benzene to phenol was prepared through modification of Keggin-structured phosphovanadomolybdate with quinine.The structure of the catalyst was fully characterized by Fourier transform infrared and ultravio- let-visible spectroscopies,X-ray diffraction,scanning electron microscopy,thermogravimetric anal- ysis,nitrogen sorption experiments,and CHN elemental analysis.The results indicated that the hybrid catalyst was a semi-amorphous heteropolyacid salt with high thermal stability,surface area,and pore volume.The catalytic activity of the hybrid for the hydroxylation of benzene with H2 O2 was assessed.The hybrid catalyst forms a liquid-solid biphasic system and exhibits high activity,con- venient recovery,and reusability.The strong electronic interactions and hydrogen bonding net- works formed between the π-electron-rich quinine framework and heteropolyanions are responsi- ble for the solid nature and insolubility of the catalyst.The high surface area and improved redox properties of the Keggin heteropolyacid account for its excellent catalytic performance.The results of this work reveal a new,more facile way to prepare an efficient polyoxometalate-based catalyst for heterogeneous hydroxylation of benzene to phenol.

关 键 词：杂多酸 多金属氧酸盐 苯羟基化 多相催化 苯酚 

分 类 号：O643.32[理学—物理化学]