氧化石墨烯固载四(对-羧基苯基)锰卟啉催化氧化甲苯

Catalytic oxidation of methylbenzene over graphene oxide immobilized manganese tetra(p-carboxylphenyl) porphyrin

为模拟细胞色素P-450酶催化活性空腔,提高昂贵金属卟啉的催化使用效率,采用改进的Hummers法制备氧化石墨烯,通过π-π非共价键以及配位作用制得氧化石墨烯固载四(对-羧基苯基)锰卟啉的仿生催化材料。采用红外可见光谱(FT-IR)、紫外可见光谱(UV-Vis)、热重分析(TG)、扫描电镜(SEM)、比表面积测试(BET)和X射线光电子能谱分析(XPS)等技术对此催化材料进行表征,并运用于催化氧化甲苯的性能研究。研究结果表明,在较优条件(170℃,0.8 MPa)下,用含0.5 mg四(对-羧基苯基)锰卟啉的催化材料催化氧气氧化甲苯可以重复使用4次,其催化氧化甲苯的平均转化率为12%,醇酮产率为5%,基本保持四(对-羧基苯基)锰卟啉对甲苯的催化活性。这表明氧化石墨烯对四(对-羧基苯基)锰卟啉的固载作用能提高金属卟啉的催化使用效率,降低金属卟啉核心催化剂的成本,具有较好的应用价值。

To simulate the catalytic cavity of Cytochrome P-450 enzyme,graphene oxide(GO)was prepared by modified Hummers method,and used for supportingmanganesetetrakis(p-carboxylphenyl)porphyrin(Mn TCPP Cl)byπ-πand coordination interactions,forminggraphene oxide-supported metalloporphyrin.The catalytic material was characterized by FT-IR and UV-Vis spectra,Thermogravimetric Analysic(TG),Scaning Electron Microscope(SEM),BET surface area measurement(BET)and X-ray photoelectron spectroscopy(XPS).Mn TCPP Cl/GO was used to catalyze methylbenzene oxidation with O 2.Under optimum oxidation conditions(170℃,0.8 MPa),only 0.5 mg of graphene oxide immobilized manganesetetrakis(p-carboxylphenyl)porphyrin were reused 4 times.On average,the methylbenzene conversion was 12%and the yields(ketone and alcohol)was 5%.These suggest that the catalytic material is better than the manganesetetrakis(p-carboxylphenyl)porphyrin.