npb-SiO_(2)-(Ag)S-Co TPyP催化氧气氧化环己烷性能研究

Study on catalytic performance of O_(2) oxidation of cyclohexane over npb-SiO_(2)-(Ag)S-Co TPyP

为了提高5,10,15,20-四(4-吡啶基)钴卟啉(Co TPyP)的催化性能,通过模拟细胞色素P 450酶的纳米腔结构和轴向硫配位作用,实现对环己烷的绿色高效催化氧化作用。将Co TPyP通过硫配位作用固载到硫银改性二氧化硅纳米多孔棒(npb-SiO_(2)-(Ag)S)的纳米腔中,形成仿生催化材料npb-SiO_(2)-(Ag)S-Co TPyP;应用各种表征技术对所制备的催化材料进行表征,并用于研究催化环己烷的氧化。结果表明:npb-SiO_(2)-(Ag)S-Co TPyP是一种良好的催化材料,在最佳催化氧化反应条件下(反应温度160℃,氧气压力0.9 MPa,催化剂量0.5 mg,反应时间4 h)可循环利用6次,平均固载催化剂转化频率为20.2×10^(4) h^(-1),环己烷的转化率为27.8%和醇酮产率是13.5%,表明Co TPyP以轴向硫配位作用方式固载到npb-SiO_(2)-(Ag)S的纳米腔中,其催化活性和稳定性获得了显著提升。

In order to improve the catalytic performance of 5,10,15,20-tetrakis(4-pyridyl)cobalt porphyrin(Co TPyP),it was proposed to simulate the nanocavity structure and axial sulfur coordination of cytochrome P-450 enzyme for realizing a green highly-efficient catalysis of cyclohexane oxidation.Co TPyP was coordinated to the sulfur-silver modified silica nanoporous bar(npb-SiO_(2)-(Ag)S)by sulfur atom,forming the biomimetic catalytic material,npb-SiO_(2)-(Ag)S-Co TPyP.The as-prepared catalyst material was characterized by various characterization techniques and used to study the catalysis of cyclohexane oxidation.The results show that npb-SiO_(2)-(Ag)S-Co TPyP is an excellent catalyst material under the optimal catalytic oxidation reaction conditions(reaction temperature 160℃,oxygen pressure 0.9 MPa,amount of catalyst 0.5 mg).It can be recycled for 6 times.On average,the conversion frequency,the conversion of cyclohexane,and the yield of alcohol and ketone are 20.2×10^(4) h^(-1),27.8%and 13.5%,respectively.This indicates that the catalytic activity and stability of Co TPyP are significantly improved after being immobilized in the nanocavity of npb-SiO_(2)-(Ag)S by means of axial sulfur coordination.