探索氧化锌固载四(4-羟基)苯基锰卟啉的催化性能。用混合溶剂法直接合成四(4-羟基)苯基卟啉(H2 THPP),采用研磨法合成四(4-羟基)苯基锰卟啉[Mn(Ⅲ)THPP]。将Mn(Ⅲ)THPP固载到新生成的氢氧化锌沉淀上,经烘焙制得氧化锌固载四(4-羟基)苯基锰卟啉催化剂。用紫外和红外光谱对它进行表征。研究固载催化剂[Mn(Ⅲ)THPP/ZnO],在无任何溶剂和还原剂的条件下,催化氧化甲苯的性能。结果表明:在最适合的180℃和0.5 MPa的反应条件下,用仅含2.7×10^-6mol Mn(Ⅲ)THPP的固载催化剂就可以连续催化13次,甲苯的平均转化率可达7.28%,醛醇选择性可达60.5%,转化数为4.83×10^4,比未固载的Mn(Ⅲ)THPP催化效率强13倍。
The catalytic performance of meso-tetra(4-hydroxylpheny1)porphyrin supported on ZnO was investigated.Meso-5,10,15,20-tetra(4-hydroxylpheny1) porphyrin(H2 THPP) and the corresponding manganese(Ⅲ) porphyrin[Mn(Ⅲ) THPP] were synthesized using the mixed solvent method and the solid grind method,respectively.Zinc oxide supported Mn(Ⅲ) THPP was prepared by stirring the mixture of the metalloporphyrin and freshly precipitated zinc hydroxide and then baked for some time,and it was characterized by UV-Vis and FT-IR spectroscopic techniques.The catalysis of Mn(Ⅲ) THPP/ZnO for aerobic oxidation of toluene was investigated in the absence of any solvent and reductant.The results showed that a quantity of catalyst,containing only 2.7×10^-6 mol of Mn(Ⅲ) THPP,can be consecutively reused 13 times for toluene oxidation,on average,7.28% toluene conversion rate,60.5% selectivity for aldehyde and alcohol and a catalyst turnover number of 4.83×10^4,under the optimal reaction conditions of 180 ℃ and 0.5 MPa.The catalytic efficiency of the supported catalyst is 13 times higher than that of Mn(Ⅲ) THPP.