磁性纳米固体碱催化剂MgAl-OH-LDHs/NiFe_2O_4的合成、表征与性能研究  

Synthesis, Characterization and Properties of a Nano-scale Magnetic Solid Base Catalyst MgAl-OH-LDHs/NiFe_2O_4

作　　者：张慧[1] 徐彦红[1] EVANS David G. 段雪[1] 

机构地区：[1]北京化工大学可控化学反应科学与技术基础教育部重点实验室,北京100029

出　　处：《化学学报》2004年第8期750-756,共7页Acta Chimica Sinica

基　　金：国家自然科学基金 (No.2 0 371 0 0 6)资助项目

摘　　要：提出用镁铝水滑石包覆镍铁尖晶石 ,制备磁性纳米固体碱催化剂MgAl OH LDHs/NiFe2 O4.用XRD ,IR ,TG DTA ,BET ,XPS ,VSM和TEM等技术及丙酮缩合反应表征了催化剂的结构和性能 .结果表明该催化剂具有以NiFe2 O4为磁核 ,以MgAl OH LDHs为Br nsted碱催化活性相 ,通过Mg O Fe(Ni)和 /或Al O Fe(Ni)连接于磁核上的包覆结构 ,给出了该催化剂的结构模型 .该催化剂用于丙酮缩合反应 ,2 73K双丙酮醇转化率略高于MgAl OH LDHs,然而经外加磁场回收所得回收率大幅度提高 ,再次用于该反应仍保持较高的催化活性 .A nano-scale magnetic solid base catalyst involving NiFe 2O 4 spinel as the magnetic core affording magnetism coated with MgAl-OH-LDHs providing basic sites has been designed and synthesized. The structure and properties of the catalyst have been characterized by using XRD, IR, TG-DTA, BET, XPS, VSM, TEM and self-condensation of acetone. The results manifest that the magnetic solid base catalyst MgAl-OH-LDHs/NiFe 2O 4 has formed the hydroxyl layered double hydroxide structure with high magnetism through calcinations/rehydration processes, and the structure model of MgAl-OH-LDHs/NiFe 2O 4 has been presented. The catalyst has high catalytic activity in self-condensation of acetone. The diacetone alcohol conversion reaches 14.2% at 273 K, which is slightly higher than that of MgAl-OH-LDHs. However, after easy recovery through an exterior magnetic field, the mass recovery of MgAl-OH-LDHs/NiFe 2O 4 has been improved greatly, and considerable activity has been maintained in the second run.

关 键 词：磁性纳米固体碱催化剂 MgAI-OH-LDHs/NiFe2O4 合成 表征 性能 丙酮 缩合 

分 类 号：O643.3[理学—物理化学]