空心结构磁性固体碱催化剂Fe3O4@LDO的制备与性能

基于水滑石类化合物的复合氧化物(LDO)是一类性能优异的固体碱催化剂,对其进行改性和功能化引起了越来越多的关注。本文将空心结构和Fe_3O_4引入到镁铝复合氧化物中,制备了一种空心结构磁性固体碱催化剂Fe_3O_4@LDO。这种空心结构磁性固体碱催化剂粒子具有以镁铝复合氧化物为壳层,空心Fe_3O_4为核的核壳结构。由于其独特的空心结构,Fe_3O_4@LDO粒子的悬浊液具有良好的稳定性,将其应用于催化Knoevenagel缩合反应,达到平衡后苯甲醛的转化率约为62%,显示出较好的催化性能。同时,Fe_3O_4@LDO粒子具有较强的磁性,非常方便分离与回收,是一种性能优良的磁性固体碱催化剂。

Synthesis and Properties of the Hollow Magnetic Solid Based Catalyst Fe3O4@LDO

The mixed oxides based on layered double hydroxide (LDO) are novel solid base catalyst, and their modification and functionalization have received more and more interesting in the area of catalysis. In this paper, the hollow magnetic solid base catalyst has been (Fe₃O₄@LDO) synthesized by coating LDO onto the hollow Fe₃O₄ particles. The Fe₃O₄@LDO particles possess well defined core-shell structure with Mg-Al Mixed Oxides as the shell and hollow Fe₃O₄ particle as the core. Owing to its unique hollow structure, the Fe₃O₄@LDO particles possess high colloid stability, and showing promising application in homogeneous catalysis. In the Knoevenagel condensation of benzaldehyde with ethyl acetoacetate under solvent free conditions, the Fe₃O₄@LDO particles gave the highest activity with yield of 62% in 2 h, showing high catalytic activity. In the mean time, the Fe₃O₄@LDO particles have strong magnetic response, can be easily separated and recycled after a catalyst reaction.