The Preparation Of Nitrogen-containing Polymer Supported Transition Metal Catalyst And Study Of Its Heterogeneous Catalysis

In this dissertation, supported transition metal composite catalysts have been synthesized utilizing nitrogen-containing functional polymer microspheres as the support. Noble metal nanoparticles and transition metal salts were introduced as catalytic active species. The catalytically active components were immobilized firmly on the polymer support. The active component was distributed uniformly taking advantage of the optimal preparation parameters and morphology control.In ths first chapter, sea-urchin like hierarchical polystyrene/polyaniline@Au (PS/PANI@Au) catalysts were achieved through a seeded swelling polymerization, followed by a in-situ reduction. The configuration manipulation of the PANI chains resulting from the doping/dedoping procedure led to various loading amounts of Au nanoparticles. Reduction of4-nitrophenol was chosen as the probe reaction to evaluate the catalytic activity of supported Au nanocatalysts. The catalytic results indicated that dedoping treatment of the PS/PANI supports provides stronger coordinative ability to metal nanoparticles as well as more-N=groups, which results in a better catalytic performance towards the reduction of4-nitrophenol. Furthermore, the catalytic oxidation propery of polystyrene/polyaniline@Au was evaluated. However, the catalytic oxidation efficiency was suffered due to the size of gold nanoparticle. A further evaluation of other catalytic system for achieving high efficiency catalytic oxidation is required.In the second chapter, we aim to solve the problem of low catalytic oxidation efficient promoted by heterogeneous gold catalyst. Furthermore, using less expensive transition metal to replace nobel gold is also one of our goal. Hierarchical heterogeneous copper catalysts have been prepared through the copper (II) complex immobilization on the surface of polystyrene/polyaniline (PS/PANI) microspheres with oriented PANI nanofibers. PS/PANI@Cu(OSO2CF3)2exhibited excellent catalytic activity for selective aerobic oxidation of alcohols and highly efficient aerobic epoxidation of alkenes under mild conditions. The supported copper (II) catalyst maintained high levels of conversion and selectivity in these reactions after six cycles and showed good stability.In this third chapter, we aim to further improve the recyclability and reaction efficiency of heterogeneous copper catalyst system toward the alcohol oxidation and olefin epoxidation. In addition, magnetic functionality would be introduced for the rapid catalyt recycling. The PAA modified Fe3O4magnetic microspheres were obtained by solvothermal reaction, followed by in-situ radical polymerization in assistance of hydrogen bonding to form the core-shell structured Fe3O4@P4VP microspheres. The P4VP shell could anchor Fe3+during the coating of MIL-100(Fe) via the step-by-step strategy, as well as protect the magnetic core from being damaged during catalytic process. The synthesized Fe3O4@P4VP@MIL-100(Fe) catalytst showed excellent catalytic activities towards selective aerobic oxidation of alcohols and epoxidation of olefins under very mild reaction conditions. The oxidation reaction efficiency was improved in comparison to PS/PANI@Cu(OSO2CF3)2catalyst. The shell of catalytic active component MIL-100(Fe) formed on the surface of Fe3O4@P4VP supports resulted in no leaching in reaction solution. The Fe3O4@P4VP@MIL-100(Fe) catalysts could be separated and recycled by an extra magnetic field. The catalytic efficiencyof the catalysts remained after10cycles, with no obvious change in terms of morphology and porous structure. This result is significantly improved from copper anchored PS/PANI@Cu(OSO2CF3)2catalyst taking advantage of the large surface area and stable coordination structure MIL-100(Fe).