粘土层间镶嵌金属络合物催化剂——均相催化剂多相化的一种模式

CLAY-INTERCALATED METAL COMPLEX CATALYST—A MODEL OF HOMOGENEOUS CATALYST HETEROGENIZATION

粘土可膨胀层可以为金属络合物插入其层间提供不同层间距的二维空间,它可以容纳较大的反应物分子,金属络合物插入粘土层间是金属络合物催化剂多相化的一种好方法,粘土层间金属络合物催化剂活性和选择性可以同相应的均相金属络合物催化剂相媲美。从多相化催化剂的制备过程,论述了粘土对金属络合物的作用;基于粘土的化学性质和孔结构特征,阐述了粘土微环境对多相化催化剂的影响。混层粘土中有蒙脱土的可膨胀层和云母的不可膨胀层,所以累托土作为粘土层间金属络合物催化剂的担体可以提高多相化催化剂的热稳定性。

The expandable layers of clay provide two dimensional hosts with different layer distance which facilitate introduction of metal complexes. The swellability of clay interlayers is so large that it can accommodate larger reactant molecules. Intercalation of metal complexes into clays is one of the useful methods for the preparation of supported metal complex catalysts. Clay-intercalated metal complex catalysts exhibit sufficiently high activity and selectivity to make them competitive to the corresponding homogeneous metal complex catalysts. An overview of the effects of heterogenized method and clay microenvironment on the clay-intercalated metal complex catalysts is discussed. The mixed- layer clay has both the expandability of montmorillonite and the stability of mica;therefore, rictorite is a good material for increasing the stability of heterogenized metal complex catalysts.