仿酶型磁性Fe^0-Fe_3O_4复合催化剂的制备及其催化性能

Preparation of Biomimetic Magnetic Fe^0-Fe_3O_4 Composite Catalyst and Its Catalytic Capability

采用原位氧化沉淀法制备出仿酶型磁性Fe0-Fe_3O_4复合催化剂,并将其作为非均相类Fenton催化剂用于溶液中对硝基苯酚的降解;采用SEM和XRD等技术对催化剂进行了表征。表征结果显示,Fe_3O_4与Fe0结合牢固,有利于Fe0的分散。实验结果表明:Fe0-Fe_3O_4对对硝基苯酚的降解为拟一级反应;在Fe0与Fe_3O_4的质量比为0.75、Fe0-Fe_3O_4投加量为1.2 g/L、初始H_2O_2浓度为10 mmol/L、初始溶液p H为3、反应温度为30℃的条件下反应90min,反应速率常数为0.067 min-1,COD去除率为77.28%,Fe溶出量为2.12 mg/L;在对硝基苯酚的降解过程中,pH先增大后减小,Fe溶出量先降低后升高;Fe0-Fe_3O_4是一种稳定的催化剂,可再生使用。

The biomimetic magnetic Fe^0-Fe3O4 composite catalyst was prepared by in-situ oxidation-precipitation method,and used as a heterogeneous Fenton-like catalyst in degradation of p-nitrophenol in solution. The catalyst was characterized by SEM and XRD. The characterization results indicate that Fe3O4 combines steadily with Fe^0,which is good for the desperation of Fe^0. The experimental results show that：The degradation of p-nitrophenol on Fe^0-Fe3O4 follows the pseudo-first-order kinetic law;Under the conditions of mass ratio of Fe^0 to Fe3O4 0.75,Fe^0-Fe3O4 dosage 1.2 g/L,initial H2O2concentration 10 mmol/L,initial solution pH 3,reaction temperature 30 ℃ and reaction time 90 min,the apparent reaction rate constant is 0.067 min^-1,the COD removal rate is 77.28%,and the dissolved quantity of Fe is 2.12 mg/L;During the p-nitrophenol degradation process,the solution pH decreases first and then increases,while the dissolved quantity of Fe reduces first and then rises;Fe^0-Fe3O4 is a catalyst showing good stability and reusability.