固载于SBA-15分子筛中的同双核金属配合物催化剂

合成了3种同双核金属配合物M2LCl3]Cl(L代表配体三亚乙基四胺,M代表Co,Cu,Cr),采用微波加热法合成了SBA-15分子筛,采用浸渍法将3种同双核金属配合物分别固载在表面官能化的SBA-15分子筛(SBA-15-NH2分子筛)中制得负载型催化剂。傅里叶变换红外光谱、X射线衍射、紫外可见光谱和热分析表征结果表明,同双核金属配合物被固载后,其结构仍保持完整。以环己烷氧化反应为探针反应,考察了Co2LCl3]Cl/SBA-15-NH2,Cu2LCl3]Cl/SBA-15-NH2,Cr2LCl3]Cl/SBA-15-NH2催化剂的活性,环己烷转化率分别为11.0%,49.5%,57.9%;对于Cr2LCl3]Cl/SBA-15-NH2催化剂,当分别以乙睛、丙酮和冰醋酸为溶剂时,环己烷转化率分别为57.9%,52.1%,34.2%,3次重复实验的环己烷转化率分别为57.9%,47.8%,46.5%,表明该催化剂具有较好的活性和重复使用性。

Homodinuclear Metal Complexes Encapsulated in SBA-15 Molecular Sieve as Catalyst

Three homodinuclear metal complexesM_2LCl_3]Cl(L stands for triethylenetetramine ligand,and M stands for Co,Cu or Cr)were synthesized,and SBA-15 molecular sieve was prepared by microwave heating method and were functionalized by γ-aminopropyl to produce SBA-15-NH_2 molecular sieve.The homodinuclear metal complexes were then immobilized on SBA-15-NH_2 by impregnation and used as catalysts for cyclohexane oxidation.The samples were characterized by means of FTIR,UV-Vis,XRD and TG-DTA.Structure of homodinuclear metal complexes remains unchanged after being immobilized.Catalytic activities ofCo_2LCl_3]Cl/SBA-15-NH_2,Cu_2LCl_3]Cl/SBA-15-NH_2 andCr_2LCl_3]Cl/SBA-15-NH_2 were studied by cyclohexane oxidation with H_2O_2 as oxidant.WhenCr_2LCl_3]Cl/SBA-15-NH_2 is used as catalyst and acetonitrile as solvent,cyclohexane conversions can reach 57.9%.After being used for three times,activity ofCr_2LCl_3]Cl/SBA-15-NH_2 catalyst can still keep at 46.5%.