SBA-15固载席夫碱铜配合物的合成及催化性能研究
发布时间：2019-06-18 10:11
【摘要】：随着工业的发展,水污染问题日趋严重。合成染料具有光、热、氧化稳定性,具有生物毒性,难以生物氧化降解。导致染料生产和印染行业产生的染料废水,是难处理的废水,对环境和人类健康等造成了严重危害。因此,有效处理染料废水成为了行业发展的关键问题。有研究表明,过渡金属有机配合物能模拟天然酶的活性,对染料废水的处理具有一定的催化效果。这类催化剂存在活性中心易流失、结构不稳定等缺陷。有文献报道SBA-15等固载酶和配合物催化剂,能增加催化剂的稳定性。本文制备了SBA-15固载席夫碱铜配合物,作为催化剂进行染料脱色降解实验,主要本研究内容和结果如下:1)以SBA-15、胺丙基三乙氧基硅烷、芳香醛为原料,制备了Schiff base 1-4@SBA-15;以SBA-15、氯丙基三乙氧基硅烷、二胺化合物、芳香醛为原料,合成了Schiff base5-9@SBA-15。以Schiff base 1-9@SBA-15与CuCl_2为原料,制备了Cu-Schiff base1-9@SBA-15。利用FT-IR、固体漫反射、Cu负载量测量、热重分析、XRD(广角、小角)、TEM、SEM、XPS等对它们进行了表征,发现Cu-Schiff base成功固载到SBA-15,且没有破坏SBA-15的结构。2)催化剂用量为4mg/L(甲基橙浓度30mg/L)条件下,考察了氧源、pH、温度、盐的种类和浓度、H_2O_2用量对Cu-Schiffbase1-9@SBA-15催化甲基橙的降解效果的影响。发现H_2O_2为有效氧源;pH升高有利于催化活性;温度升高有利于染料降解;-3-24-l、、NOSOC存在不影响染料的完全降解;-2-rNOB、存在,染料降解率只有80%左右,不能完全降解。选择染料降解的最适条件:H_2O_2为氧源、(7)(8)(7)染料双氧水(8)1:400n:n(28)、pH=9.1、T=40℃。3)以H_2O_2为氧源、n双氧水:n染料=400:1、pH=9.1、T=40℃,催化剂用量为4mg/L(染料浓度30mg/L)条件下,考察了Cu-Schiffbase@SBA-15催化不同底物:甲基橙、罗丹明B、茜素红、R、E、O、B等7种染料的降解效果。发现对于罗丹明B的降解效果最好,1.5hs可达到100%的降解率;对含硝基、溴等取代基团的染料R、E、O、B等降解效果较差,48h只有80%的降解率;说明催化剂Cu-Schiffbase@SBA-15具有一定的底物选择性。4)考察了催化剂Cu-Schiffbase的构效关系,发现链的延伸有利于催化活性,刚性增加使催化活性下降,给电子取代基能促进催化活性。5)考察了催化剂Cu-Schiff base的循环使用、机械稳定性和酸碱稳定性。发现5-6次循环后催化效果不变,N_2吸附类型不变,说明催化剂可循环使用,具有好的机械稳定性。发现酸性条件下催化剂失活,加碱后可以恢复催化活性;在碱性条件下催化剂失活,加酸后催化活性不恢复,说明催化剂在酸到弱碱性条件下稳定,在强碱性条件下结构不稳定。6)利用UV-vis、HPLC、CO_2的吸收实验测定了降解产物,采用Mn法测定了降解前后的COD。发现苯环区吸收消失,降解产物有顺丁烯二酸、草酸和CO_2,降解后COD为3-6.5mg/L。说明染料发生了降解,甚至达到矿化。7)利用Graph Pad Prism 5软件对催化剂降解甲基橙进行了动力学模拟,发现催化剂对甲基橙的脱色降解具有酶学特性,符合Michaelis-Menten动力学模型规律。说明配合物固载后保留了仿酶活性。8)利用自由基捕捉实验和自由基抑制实验,发现水杨酸捕捉了羟基生成了2,5-二羟基苯甲酸,利用叔丁醇可以抑制染料的脱色降解,说明制备的催化剂在催化降解底物时的活性组分包括羟基自由基,并给出了可能的染料分子降解过程。
[Abstract]:With the development of industry, the problem of water pollution is becoming more and more serious. The synthetic dye has the advantages of light, heat, oxidation stability, biological toxicity and difficult biological oxidation and degradation. The dye waste water produced by the dye production and dyeing industry is a difficult-to-treat waste water, and has serious harm to the environment and human health and the like. Therefore, the effective treatment of dye wastewater has become a key issue in the development of the industry. It is shown that the transition metal organic complex can simulate the activity of the natural enzyme and has a certain catalytic effect on the treatment of the dye wastewater. The catalyst has the defects of easy loss of active center, unstable structure and the like. It is reported that SBA-15 and other immobilized enzymes and complex catalysts can increase the stability of the catalyst. In this paper, an SBA-15 Schiff base copper complex is prepared, which is used as a catalyst to decolor and degrade the dye. The main contents and results of this study are as follows:1) The Schiff base 1-4@SBA-15 is prepared by using SBA-15, aminopropyltriethoxysilane and aromatic aldehyde as raw materials; SBA-15, chloropropyltriethoxysilane, Schiff base 1-9@SBA-15 was synthesized with Schiff base 1-9@SBA-15 and CuCl _ 2 as a raw material. Cu-Schiff base 1-9@SBA-15 was prepared by FT-IR, solid diffuse reflection, Cu loading measurement, thermogravimetric analysis, XRD (wide angle, small angle), TEM, SEM and XPS. And the effect of the amount of H _ 2O _ 2 on the degradation effect of the Cu-Schiffbase1-9@SBA-15-catalyzed methyl orange was investigated. It is found that H _ 2O _ 2 is the effective oxygen source; the pH increase is favorable to the catalytic activity; the temperature increase is favorable to the degradation of the dye;-3-24-l, and the NOSOC does not affect the complete degradation of the dye;-2-rNOB, the dye degradation rate is only about 80%, and can not be completely degraded. The optimum conditions for the degradation of dye are as follows: H _ 2O _ 2 is oxygen source, (7) (8) (7) dye hydrogen peroxide (8)1: 400n: n (28), pH = 9.1, T = 40 鈩，
本文编号：2501393
[Abstract]:With the development of industry, the problem of water pollution is becoming more and more serious. The synthetic dye has the advantages of light, heat, oxidation stability, biological toxicity and difficult biological oxidation and degradation. The dye waste water produced by the dye production and dyeing industry is a difficult-to-treat waste water, and has serious harm to the environment and human health and the like. Therefore, the effective treatment of dye wastewater has become a key issue in the development of the industry. It is shown that the transition metal organic complex can simulate the activity of the natural enzyme and has a certain catalytic effect on the treatment of the dye wastewater. The catalyst has the defects of easy loss of active center, unstable structure and the like. It is reported that SBA-15 and other immobilized enzymes and complex catalysts can increase the stability of the catalyst. In this paper, an SBA-15 Schiff base copper complex is prepared, which is used as a catalyst to decolor and degrade the dye. The main contents and results of this study are as follows:1) The Schiff base 1-4@SBA-15 is prepared by using SBA-15, aminopropyltriethoxysilane and aromatic aldehyde as raw materials; SBA-15, chloropropyltriethoxysilane, Schiff base 1-9@SBA-15 was synthesized with Schiff base 1-9@SBA-15 and CuCl _ 2 as a raw material. Cu-Schiff base 1-9@SBA-15 was prepared by FT-IR, solid diffuse reflection, Cu loading measurement, thermogravimetric analysis, XRD (wide angle, small angle), TEM, SEM and XPS. And the effect of the amount of H _ 2O _ 2 on the degradation effect of the Cu-Schiffbase1-9@SBA-15-catalyzed methyl orange was investigated. It is found that H _ 2O _ 2 is the effective oxygen source; the pH increase is favorable to the catalytic activity; the temperature increase is favorable to the degradation of the dye;-3-24-l, and the NOSOC does not affect the complete degradation of the dye;-2-rNOB, the dye degradation rate is only about 80%, and can not be completely degraded. The optimum conditions for the degradation of dye are as follows: H _ 2O _ 2 is oxygen source, (7) (8) (7) dye hydrogen peroxide (8)1: 400n: n (28), pH = 9.1, T = 40 鈩，
本文编号：2501393
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