| 羟基铁柱撑蒙脱土-δ-MnO2复合体Fenton催化降解亚甲基蓝 |
| Heterogeneous Fenton Degradation of Methylene Blue by δ-MnO2-Coated Fe-Pillared Bentonite |
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| 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pH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pH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。 |
| 关键词: 铁柱撑蒙脱土-δ-MnO2复合体 异相催化 亚甲基蓝 |
| 基金项目: 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。 |
| Abstract: 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 catalysts 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 SBET values of the samples were increased after pillaring compared with bentonite. The catalytic activity of different samples was estimated by measuring the degradation rate of methylene 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 pH value on MB degradation were studied. The results showed that the catalytic activity of δ-MnO2-coated Fe- pillared 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. |
| Keywords: δ-MnO2-coated Fe-pillared bentonite Heterogeneous catalysis Methylene blue |
| 投稿时间：2014-09-24 修订日期：2014-12-23 |
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| 石中亮,王兴星,姚淑华.羟基铁柱撑蒙脱土-δ-MnO2复合体Fenton催化降解亚甲基蓝[J].无机化学学报,2015,31(4):696-702. |
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