羟基铁柱撑蒙脱土-δ-MnO_2复合体Fenton催化降解亚甲基蓝  

Heterogeneous Fenton Degradation of Methylene Blue by δ-MnO_2-Coated Fe-Pillared Bentonite

作　　者：石中亮[1] 王兴星[1] 姚淑华[1] 

机构地区：[1]沈阳化工大学应用化学学院,沈阳110142

出　　处：《无机化学学报》2015年第4期696-702,共7页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学基金(No.41373127);辽宁省自然科学基金项目(No.2013020121)资助

摘　　要：制备了一系列羟基铁柱撑蒙脱土-δ-MnO2复合材料,采用X射线粉末衍射(XRD)、比表面积(SBET)及扫描电子显微镜(SEM)研究其结构特征。结果显示:钙基蒙脱土的层间距为1.47 nm,经过柱撑之后,羟基铁撑蒙脱土的层间距增大到1.51 nm,羟基铁柱撑蒙脱土-δ-MnO2复合体为1.55 nm左右,并且比表面积较原土也有明显的增大。以亚甲基蓝为目标污染物,研究了其作为异相催化剂的催化性能,考察了溶液H2O2加入量、δ-MnO2含量及p H值等对亚甲基蓝降解性能的影响。结果表明,在实验条件下,催化剂的催化活性随H2O2浓度的增加而升高,当nFe/nMn=0.241时,催化活性最好,且有较大的p H适用范围。亚甲基蓝的异相催化降解过程符合准一级动力学方程。催化剂循环使用3次,仍然具有良好的活性。A series of δ-MnO2-coated Fe-pillared bentonite composite materials were synthesized and the samples were used as catalysts for the heterogeneous Fenton degradation of methylene blue.The microstructure of the cat-alysts was characterized by X-ray diffraction（XRD）, specific surface area measurements（SBET）,scanning electron microscopy（SEM）. The results showed that the pillaring process increased the basal spacing（d001） from 1.47 nm for bentonite（MTT） to 1.51 nm for the Hydroxyl-pillared bentonite（H-Fe-P-E） and 1.55 nm for the δ-MnO2-coated Fe-pillared bentonite（H-Fe-P-E-M）. The SBETvalues of the samples were increased after pillaring compared with bentonite. The catalytic activity of different samples was estimated by measuring the degradation rate of methy-lene blue（MB） in aqueous solution at MB concentration=50 mg·L-1,catalyst dosage=0.1 g·L-1,T=25 ℃,and the effects of various experimental parameters such as initial H2O2 concentration, δ-MnO2 content and initial solution p H value on MB degradation were studied. The results showed that the catalytic activity of δ-MnO2-coated Fepillared bentonite increased with H2O2 concentration and reached a optimal catalytic result when the molar ratio of nFe/ nMn=0.241. The kinetics of degradation reaction can be expressed by the first-order reaction kinetic model. In addition, the recyclability of the prepared catalyst is also confirmed. The catalyst retains high activity after being used three times.

关 键 词：铁柱撑蒙脱土-δ-MnO2复合体 异相催化 亚甲基蓝 

分 类 号：O643[理学—物理化学]