Design of a molecular-imprinted Rh-amine complex on a SiO_2 surface and its catalytic behavior for alkene hydrogenation

摘要

A molecular-imprinted Rh-amine complex on a SiO_2 surface is designed by metal-complex attaching and molecular imprinting techniques. alpha-methylbenzylamine is used as a template molecule, which has a similar shape to a half-hydrogenated species of alpha-methylstyrene. Rh(C_3H_5)_3 is attached on a SiO_2 surface, and a template amine ligand is coordinated to the attached Rh complexes. The amine template promotes the hydrolysis-polymerization of Si (OCH_3)_4 and surface SiO_2-matrix overlayers are formed on the surface surrounding the attached Rh-amine complexes. After the final extraction of the template, an unsaturated Rh complex and a template-shaped cavity are created in the surface pore of the SiO_2-matrix overlayers. The imprinted catalyst exhibited high catalytic activity and durability for the alkene hydrogenation. Furthermore, shape-selective behavior was observed on the imprinted catalyst by the use of seven amines as inhibiters for the alkene hydrogenation.