Metal Organic Framework:preparation Of SnCl₄ And Polymer Complex And Its Catalytic Conversion Of Sugar Of Performance Research

Saccharides, which is green, reproducible and abundant in biomass, can be transformed into high value-added products by chemical technique. This is significance in sustainable development for human beings. Catalysts play a pivotal role in the conversion. So far, research results have showed that Lewis acid and Bronst acid compound catalyst is efficient in the catalysis reaction for the transformation from saccharides to lactic。We have used benzoxazine and Sn Cl4 as raw material, prepared Metal Organic Framework Lewis acid and Bronst acid compound solid catalyst by inverse suspension curing method. We evaluated the catalyst by catalyzing sucrose converting to methyl lactate in methanol. We have characterized the structure and property of the catalyst by X-ray diffraction(XRD)、Scanning electron microscope(SEM)、Fourier transform infrared spectroscopy(FT-IR)、X-ray photoelectron spectroscopy(XPS) and Energy Dispersive Spectrometer(EDS). The influence factors of the property of the catalyst we have researched are mass ratio of raw material, structure of benzoxazine temperature and method of solidification. We also investigated how the factors such as temperature of conversion reaction, reaction time, dosage of catalyst and solvent affect the productive rate of methyl lactate. We then analyzed the difference in catalytic activity when using sucrose, glucose, fructose as the substrate. At last, we explored the role of Sn Cl4 and benzoxazine in the catalytic process and the catalytic mechanism of this novel metal-organic framework catalyst.The research result shows that this metal-organic framework catalyst has a peculiar structure that consists of innumerable nano-particles with the diameter between 70-100 nm. The catalyst has rough surface and rich internal hole with the diameter between 150-200 nm. This kind of structure makes it suitable for conversion of biomass. The catalytic activity mainly affected by temperature of preparation, mass ratio of raw material, the structure of ligand and the optimal condition for synthesis of catalyst is :the mass ratio of benzoxazine prepared by melamine and phenol and Sn Cl4·5H2O is 20%, the temperature of solidification is 200 ℃. The optimal condition of the catalytic reaction is 800 mg catalyst, 80 m L methanol as solvent, 160 ℃as reaction temperature and the reaction time is 20 h in which the conversion of sucrose, fructose and glucose to methyl lactate was 40%, 27% and 10% respectively. In the catalytic process, Sn(Ⅳ) plays the role of promoting the dissolution of saccharides in methanol and transformation to methyl lactate while benzoxazine enhances conversion efficiency by its-OH which is faintly acid.