碳纳米管/杂多酸/聚吡咯复合催化剂的制备及催化烯烃环氧化性能

以磷钼酸(PMo)、吡咯(Py)和碳纳米管(CNTs)为原料,通过原位聚合方法制备了PPy-PMo@CNTs复合材料.采用傅里叶变换红外光谱(FTIR)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)等手段对材料进行了结构表征.结果表明,磷钼酸和聚吡咯被引入到碳纳米管载体上,且聚吡咯在碳纳米管表面形成了一层薄层.N2吸附-脱附测试结果表明,PPy-PMo@CNTs为介孔材料.将以乙腈为溶剂,过氧化氢为氧化剂的烯烃环氧化反应作为模型反应,考察了催化剂PPy-PMo@CNTs的催化活性.结果表明,在60℃,反应底物为1 mmol,催化剂投量为10 mg的条件下,该催化剂表现出较好的催化活性.中断和循环实验结果表明,催化剂具有较好的稳定性,在相同的反应条件下经过5次循环后,环辛烯的转化率依然保持在约65%.

Preparation and Catalytic Olefin Epoxidation Properties of Carbon Nanotube/Polyoxometalates/Polypyrrole Composite Catalyst

The PPy-PMo@CNTs composite materials were prepared via in situ polymerization with PMo,polypyrrole and carbon nanotube.The multiple characteristics of FTIR,SEM and TEM were used to characterize the catalysts.The results indicated that both PMo and polypyrrole were incorporated into the CNTs,and polypyrrole formed a layer on the surface of CNTs.N2-adsorption results showed that PPy-PMo@CNTs obtain uniform mesoporous structure.The catalytic properties of PPy-PMo@CNTs were investigated in olefin epoxidation using H2O2 as the oxidant and acetonitrile as the solvent.The catalytic reaction results indicated that PPy-PMo@CNTs exhibits good catalytic activity at temperature of 60 ℃ when reaction substrate was 1 mmol and dosage of catalyst was 10 mg.Leaching and recycling experiments exhibited that PPy-PMo@CNTs have excellent stability,there was no obvious decrease of cyclooctene conversion after five reaction cycles under identical reaction conditions,and the conversion of cyclooctene retains around 65%.