Epoxidation Of Αlpha-pinene Catalyzed By Non-noble Metal Supported On Amphiphilic Mesoporous Materials

2,3-epoxypinane is an important intermediate in the fields of medicine,perfume and pesticide.The traditional industrial production of 2,3-epoxypinane has some shortages,for example,low safety,requiring harsh reaction conditions,difficult purification on product and environmental pollution.As a green oxidant with advantages of good safety and high reactivity in mild conditions,hydrogen peroxide has become one of the best oxidants for various oxidation reactions.In this thesis,the epoxidation ofα-pinene by hydrogen peroxide would be discussed.In aqueous condition,a proper selection of applied catalyst is of great importance for improving the synthetic yield of the catalytic epoxidation ofα-pinene with H₂O₂ by reducing the contact resistance between oil phase and water phase.With good hydrophilicity and hydrophobicity,amphiphilic catalyst can effectively promote the epoxidation ofα-pinene via increasing the contact area of the reaction and the concentration of substrates.Herein,the preparation of new types of amphiphilic catalysts and their catalyzed epoxidation ofα-pinene would be mainly discussed.Amphiphilic mesoporous core-shell materials TS-1@Si/C are prepared by hydrothermal method using tetrapropylammonium hydroxide as template,tetrabutyl titanate as titanium source,tetraethyl silicate as silicon source,ammonia as alkali source and resorcinol as carbon source.The morphology,structure and amphiphilicity of TS-1@Si/C were characterized by SEM,XRD,XPS,ICP and contact angle measurements.With this catalyst,the optimal condition for the catalyzed epoxidation ofα-pinene would be as followling:α-pinene（3 mmol）,catalyst（7.1%of the mass ratio ofα-pinene）,hydrogen peroxide（5 m L）,acetonitrile（10 m L）,water（4 m L）,potassium carbonate（2 mmol）,50 ^oC,4 h,which gives 81.41%conversion ofα-pinene and 82.80%selectivity of 2,3-epoxypinane.The catalytic activity of TS-1@Si/C would show little dropping-down after repeated use of 5 cycles.A one-pot synthetic strategy on hollow mesoporous nanomaterial Mn-N_xC@m Si O₂ has been developed by using CTAB as template,resorcinol as carbon source,tetraethyl silicate as silicon source and manganese acetate as manganese source.The morphology,structure and amphiphilicity of Mn-N_xC@m Si O₂ were characterized by TEM,FT-IR,XPS,nitrogen adsorption desorption and contact angle measurements.With this catalyst,the optimal catalyzed epoxidation ofα-pinene could give 96.38%conversion of pinene and 84.57%selectivity of 2,3-epoxypinane by following a condition ofα-pinene（3 mmol）,catalyst（4.7%of the mass ratio ofα-pinene）,hydrogen peroxide（9 mmol）,acetonitrile（12 m L）,water（12 m L）,sodium bicarbonate（5 mmol）,15 ^oC,1 h.The developed catalyst could maintain the catalytic activity very well after repeated use of 9 cycles.The results show that amphiphilic materials can increase the contact area of a system with three phases of water,oil and solid and also the concentrations of substrates which greatly improve the synthetic efficiency of the catalyzed epoxidation ofα-pinene in aqueous condition and meanwhile realize the easy separation of catalyst and product.By affording a new solution on the application of non-noble metals in catalytic field,this work would provide a new synthetic strategy for the epoxidation ofα-pinene,as well as a new idea for the epoxidation of other olefins in aqueous condition.