Design,Assembly And Properties Of Porous Metal-Organic Framework Catalysts

The metal-organic framework is usually supported by a multi-coordination group as a skeleton,and is obtained by a self-assembly method using an inorganic metal as a node,and is a novel porous material.Due to its high specific surface area and porosity,it is widely used in gas storage and separation,sustainable energy,molecular recognition,and supercapacitors.In this paper,we designed amino acid,Schiff base and urea base as the starting materials,and designed bridged ligands with different sizes and coordination modes,and synthesized metal-organic framework materials with different functions by simple hydrothermal method.The complexes were studied and characterized by thermogravimetric analysis,powder X-ray diffraction,Fourier transform infrared spectroscopy and single crystal X-ray diffraction.The application prospects of complex materials in heterogeneous asymmetric catalysis are mainly investigated.Firstly,a copper-based metal-organic framework material 1 was designed and synthesized by a simple solvothermal method using a three-foot Schiff base ligand and copper ions.The framework material and Cd²⁺ions were then synthesized by solvothermal method to form a metal-organic Frame material 2,and found that complex2 has good catalytic performance,only 1.5 mol%of the loading,the Henry reaction can get up to 97%yield.High conversion rates can also be achieved at low catalyst loadings.However,only a low conversion rate can be obtained at a low catalyst loading,which indicates that complex 2 is a catalyst with high synergistic catalytic performance and has great research potential in the field of synergistic catalysis.Then,a urea-containing organic ligand was synthesized,and the ligand and Cu²⁺ion were synthesized by solvothermal method to synthesize 2D copper-based metal-organic framework material3.The catalytic performance of 3 in silicon cyanidation reaction was tested and found.When the complex 3 catalyzes the reaction,the substrate with the electron-donating group can have a conversion rate of up to 97%,and the substrate with the electron-withdrawing group has a conversion rate of only 54%,so the complex 3 pairs the electron-donating group.The substrate of the group has good catalytic properties.Finally,a V-type ligand was designed and synthesized by using L-valine as a raw material.A 2D porous framework material was synthesized by simple solvothermal reaction with Cu²⁺ions.After the heat activation treatment,the catalytic performance was investigated.The experimental data show that the complex 4 can catalyze the Friedel-Crafts alkylation reaction of trans-nitrostyrene with hydrazine at room temperature and obtain a yield of 78%.Moreover,we also found that Complex 4exhibited good recyclability and maintained a 70%yield after four cycles.The main work studied in this paper plays an important role in the design and synthesis of a series of heterogeneous complex catalysts.