Photocatalytic Oxidation Of Glucose By Supported Iron Alkylthio Porphyrazine

Glucose is a rich and renewable biomass in nature,its oxidation products such as glucaric acid and gluconic acid are high value-added industrial chemicals.The utilization of photocatalyst can catalyze the oxidation of glucose into high value-added oxidation products using hydrogen peroxide or molecular oxygen as the oxidant,which is in line with the concept of sustainable green development.The metallothioporphyrzine is a kind of compound with a tight macrocyclic structure and a delocalized?-electron system.As a photocatalyst,it can simulate the activation of hydrogen peroxide or molecular oxygen to produce reactive oxygen species under mild conditions,this process is a green catalytic process.In this thesis,a series of high value-added chemicals were obtained by photocatalytic oxidation of glucose with supported iron tetra?2,3-bis?butylthio?maleonitrile?porphyrazine.The main work of this thesis is as follows:?1?Supported H-ZSM-5/FePz?SBu?₈ was prepared by loading H-ZSM-5 onto the surface of FePz?SBu?₈.Using hydrogen peroxide as the oxidant,the photocatalytic performance of H-ZSM-5/FePz?SBu?₈ under visible light???420nm?irradiation was studied by catalytic oxidation of glucose.The effects of illumination wavelength,FePz?SBu?8 loading and the amount of hydrogen peroxide on the activity of the catalyst were further studied.The experimental results showed that H-ZSM-5/FePz?SBu?8 exhibited excellent photocatalytic activity for oxidation of glucose into high value-added chemicals.For example,the conversion of glucose reaches up to 35.8%after reaction of 4 h,and its oxidation products including glucaric acid,gluconic acid,arabinose,glycerol and formic acid were obtained,the selectivities of these products were 13.1%,31.9%,17.3%,13.0%and 1.7%,respectively.The results obtained from ESR technology and quenching experiments showed that the main reactive oxygen species in the photocatalytic system were hydroxyl radical?·OH?and superoxide anion(O₂^·-).A series of comparative experiments and intermediate analysis indicated that the possible pathway of glucose oxidation is to first oxidize glucose to gluconic acid and glucuronic acid,and these two oxidation products are further oxidized to glucaric acid,which could be further oxidized to other oxidation products.?2?BiOCl/FePz?SBu?₈ was prepared by loading FePz?SBu?₈ onto the surface of support BiOCl.The photocatalytic oxidation of glucose by BiOCl/FePz?SBu?₈ was studied using molecular oxygen as the oxidant.Furthermore,the effects of FePz?SBu?8 loading,light intensity and substrate concentration on catalytic activity were studied.Using the xenon lamp as the light source,the conversion of glucose reached up to 70.4%after reaction of 1 h,and the oxidation products were mainly gluconic acid,arabinose and erythrose,their selectivities are 6.7%,33.8%and 54.1%,respectively.The total selectivity of oxidation products reached up to 94.6%.The results obtained from ESR technology and quenching experiments showed that the active species in the photocatalytic system were mainly hydroxyl radicals?·OH?,singlet oxygen?¹O₂?and superoxide anions(O₂^·-)and holes?h⁺?.Furthermore,product analysis indicated that the possible pathway for glucose oxidation was to first generate gluconic acid from the glucose oxidation and further oxidize to arabinose and erythrose.?3?Using hydrogen peroxide as the oxidant,the photocatalytic performance of BiOCl/FePz?SBu?₈ for oxidation of glucose under visible light???420nm?was studied.The effects of FePz?SBu?8 loading,substrate concentration and light intensity on the catalytic activity were also studied.Under the optimal conditions,the conversion of glucose could reach up to 45.3%,and the selectivity of glucaric acid and gluconic acid are 7.0%and 20.0%,respectively.A small amount of arabinose,formic acid and glycerol are also obtained.In the meantime,the amount of hydrogen peroxide can also affect the selectivity of the oxidation products.The results obtained from ESR technology and quenching experiments showed that the active species of the photocatalytic system were hydroxyl radical?·OH?,singlet oxygen?¹O₂?,superoxide anion(O₂^·-)and hole?h⁺?.Furthermore,the results obtained from photocurrent indicated that there existed a synergistic effect between FePz?SBu?8 and BiOCl.