Investigation In Photocatalytic Oxidation Of Benzyl Alcohol And Methyl Phenyl Sulfide With The Supported Heterogenous Catalyst

Supported heterogeneous catalyst plays a decisive role in industrial design and production.In recent years,scientists have done a lot of research to improve their catalytic properties.Photocatalysis,as a new type of clean and environment-friendly catalytic method,is worth our efforts in this regard to try a new catalytic scheme.We mainly enhance its photocatalytic activity in two ways.The first is to change the pores of the catalyst and increase the specific surface area,which makes it easier for the catalyst to contact with light and enhance the absorption of light;the second is to change the heterojunction type,to decrease the probability of hole-electron recombination,and enhances its optical activity.In Chapter 1,it mainly introduces the principle and current situation of photocatalysisand focuses on the design ideas and methods of supported photocatalysts.In Chapter 2,eight sulfur-containing tetraazaporphyrins such as MPhNO₂（SBu）₆Pz and M（SBu）₈Pz（M=Zn,Ni,H₂）were synthesized.The macrocyclic structure can prepare for the next step of catalysis.It was characterized by 1H-NMR,UV-Vis,FI-IR and MALDI-TOF MS.MPhNO₂（SBu）₆Pz and M（SBu）₈Pz（M=Zn,Ni,H₂）were successfully synthesized and characterized by MALDI-TOF MS,UV-Vis.In Chapter 3,starting from increasing the specific surface area of the catalyst,the ZSM-5 zeolite was loaded with the above-mentioned sulfur-containing tetraazaporphyrin complex,and the photocatalytic oxidation of benzyl alcohol was investigated.The tetrazaporphyrins were successfully loaded into the stacking channels of zeolites by impregnation method.The photocatalytic performance of benzyl alcohol in water was studied.Characterization of the catalyst by basic means such as TEM,UV-vis and XRD.The ability of photocatalysis was studied from the aspects of acidity and alkalinity of the catalyst,light intensity,symmetry of the porphyrin molecule,oxidation ability of the center metal,and the size of the load.It is inferred that the loading of sulfur-containing tetraazaporphyrins can increase the selectivity of photocatalytic to benzoic acid,among which the asymmetric nitro CoPhNO₂（SBu）₆Pz has the best performance and can selectively oxidize benzyl alcohol to benzoic acid.However,the catalyst is unstable.After repeated use,the activity declines seriously.The Chapter 4,it starts with the optical conductivity of the composite catalyst to increase the separation of holes and electrons.The catalyst-free C₆₀/g-C₃N₄ catalyst is used in the literature for the photocatalytic oxidation of sulfides to sulfoxides under mild condition.The catalysts were characterized by means of XPS,SEM,TEM,UV-vis,FI-IR,PL and XRD.Under the irradiation of visible light,the thioether can be selectively oxidized to sulfoxide with methanol as a solution and the composite catalyst C₆₀/g-C₃N₄ can be used and exhibits good selectivity（99%）and conversion rate（99%）.The different solvents,illumination time,the universality of the reaction substrate,and the effect of loading on the selective oxidation of thioethers were studied.According to ESR and related comparative experiments,it was determined that the active oxidants produced in photocatalysis were·O^2-and ¹O₂.At the same time,the composite catalyst C₆₀/g-C₃N₄ showed good stability and universal applicability,and the sulfides of various structures were converted to the corresponding sulfoxides and were not deactivated after repeated use.