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.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
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
