Preparation and application of heterogeneous catalyst PCuMo 11 / nitrogen rich covalent organic framework material for olefin epoxidation with molecular oxygen oxidant

Epoxide is an important organic synthesis intermediate and chemical raw material that is mainly prepared from the olefin epoxidation. It is a very interesting work to prepare efficient catalysts with stability and recyclability for aerobic olefins epoxidation. Composite PCuMo11/PC was prepared by using the nitrogen rich covalent organic framework material (PC) as support and the polyoxometalate PCuMo11 as active substance. The materials were characterized by FT-IR, N2 adsorption and desorption, XPS, TEM and EDS. The application of PCuMo11/PC for heterogeneous catalytic epoxidation of olefins (styrene, 1-octene, cyclooctene, cyclododecene) with molecular oxygen oxidant has obtained high catalytic activity and selectivity. There was no significant decrease in catalytic activity after recycling over five times. The experimental results show that large surface area and rich nitrogen content in the skeleton of the two-dimensional layered nitrogen rich covalent organic framework material are benefit to disperse the catalytic active substance polyoxometalate uniformly and establish a relatively stable chemical link, so as to improve the catalytic activity and stability of the composite.