Synthesis Of Metal Phthalocyanine/Carbon Nanotubes Composites And Their Performance In Catalytic Oxidation

In recent years,metal phthalocyanine has been used as a catalyst for different synthetic reactions.Different metals inserted into the center of the phthalocyanine ring exhibit different catalytic activities in specific reactions.However,due to the structural characteristics of the metal phthalocyanine,it is easy to aggregate and accumulate in the reaction system,resulting in greatly reduced solubility and catalytic activity in organic solvents.In addition,metal phthalocyanine also faces the problem of poor reusability.In order to address the shortcomings of the metal phthalocyanine catalyst,fixing the metal phthalocyanine compound on carbon nanotubes actively can reduce the agglomeration of metal phthalocyanine catalyst powder,and improve the activity and stability of the catalyst furtherly.Based on the shortcomings of metal phthalocyanine that is easy to aggregate and poor to stabilize in practical applications,this subject uses carbon nanotubes as carriers to conduct modification of metal phthalocyanine.Thus,the dispersibility of metalphthalocyanine can be enhanced,and the catalytic activity and stability of the metal phthalocyanine in catalytic reactions can be improved.The specific studies are as follows:1.Synthesized by phthalonitrile liquid phase method,the Co Pc（O₂C₇H₆）₄was loaded on the carbon nanotubes by ultrasonic oscillation to obtain Co Pc（O₂C₇H₆）₄/MWCNTs composite material.UV-Vis,XRD and other methods were used to characterize the structure of composites.The catalytic oxidation reaction of benzyl alcohol was performed with the Co Pc（O₂C₇H₆）₄/MWCNTs composite as a catalyst.The solvent,benzyl alcohol to catalyst mass ratio,temperature and time factors were screened.Under optimal conditions,the conversion rate of benzyl alcohol was 50.02%,and the selectivity of benzaldehyde was88.98%.Finally,the possible mechanism of catalytic oxidation of benzyl alcohol was discussed.2.Synthesized by phthalonitrile liquid phase method,the MPc(OC₁₀H₁₄N)₄ of four of different central ions（Co,Ni,Cu and Zn）were loaded on the carbon nanotubes by ultrasonic oscillation to obtain MPc(OC₁₀H₁₄N)₄/MWCNTs composite materials.The catalytic oxidation reaction of styrene was performed with the four MPc(OC₁₀H₁₄N)₄/MWCNTs composite as catalysts.The solvent,styrene to catalyst mass ratio,temperature and time factors were screened.At the same time,blank experiments were performed and the catalytic activity of the four metal phthalocyanines was compared.It was found that Cu Pc(OC₁₀H₁₄N)₄/MWCNTs composite performed the highest catalytic performance,and under optimal conditions,the conversion rate of styrene was 99.18%,at the same time,the selectivity of benzaldehyde was57.50%.Finally,the possible mechanism of catalytic oxidation of styrene was discussed.3.The CuTNPc/MWCNTs composite was synthesized using 4-Nitrophthalonitrile,monohydrate copper acetate and carbon nanotube in the presence of DBU as a catalyst by a simple in situ solvothermal method.UV-Vis,XRD,FT-IR,SEM,TEM,Raman and TGA were used for the characterization of prepared composite.In the catalytic oxidation of styrene,screening experiments such as solvent,oxygen source types,mass of catalyst and temperature were performed.Under the optimal conditions,the styrene conversion rate was 99.74%,and the selectivity of benzaldehyde was 79.53%.4.Two CuTABPPc of different substitution positions（αandβposition）were synthesized by phthalonitrile liquid phase.Theα-Cu TABPPc/MWCNTs composite andβ-Cu TABPPc/MWCNTs composite were successfully fabricated by the method of chemical grafting.In the catalytic oxidation of styrene,screening experiments were performed on the conditions of solvent and oxygen source types,mass of catalyst,temperature and time.At the same time,blank experiments were performed,and under the optimal conditions,the conversion of styrene was 99.25%and the selectivity of benzaldehyde was 78.03%whenα-Cu TABPPc/MWCNTs composites were used as catalysts;99.33%conversion of styrene and 77.44%selectivity of benzaldehyde were achieved whenβ-Cu TABPPc/MWCNTs composites were used as catalysts.Finally,reproducible experiments were performed on the two composite catalysts and the reusability performance of theα-CuTABPPc/MWCNTs composites was explored.