SBA-15固載席夫堿銅配合物的合成及催化性能研究
發(fā)布時間：2019-06-18 10:11
【摘要】：隨著工業(yè)的發(fā)展,水污染問題日趨嚴重。合成染料具有光、熱、氧化穩(wěn)定性,具有生物毒性,難以生物氧化降解。導致染料生產(chǎn)和印染行業(yè)產(chǎn)生的染料廢水,是難處理的廢水,對環(huán)境和人類健康等造成了嚴重危害。因此,有效處理染料廢水成為了行業(yè)發(fā)展的關(guān)鍵問題。有研究表明,過渡金屬有機配合物能模擬天然酶的活性,對染料廢水的處理具有一定的催化效果。這類催化劑存在活性中心易流失、結(jié)構(gòu)不穩(wěn)定等缺陷。有文獻報道SBA-15等固載酶和配合物催化劑,能增加催化劑的穩(wěn)定性。本文制備了SBA-15固載席夫堿銅配合物,作為催化劑進行染料脫色降解實驗,主要本研究內(nèi)容和結(jié)果如下:1)以SBA-15、胺丙基三乙氧基硅烷、芳香醛為原料,制備了Schiff base 1-4@SBA-15;以SBA-15、氯丙基三乙氧基硅烷、二胺化合物、芳香醛為原料,合成了Schiff base5-9@SBA-15。以Schiff base 1-9@SBA-15與CuCl_2為原料,制備了Cu-Schiff base1-9@SBA-15。利用FT-IR、固體漫反射、Cu負載量測量、熱重分析、XRD(廣角、小角)、TEM、SEM、XPS等對它們進行了表征,發(fā)現(xiàn)Cu-Schiff base成功固載到SBA-15,且沒有破壞SBA-15的結(jié)構(gòu)。2)催化劑用量為4mg/L(甲基橙濃度30mg/L)條件下,考察了氧源、pH、溫度、鹽的種類和濃度、H_2O_2用量對Cu-Schiffbase1-9@SBA-15催化甲基橙的降解效果的影響。發(fā)現(xiàn)H_2O_2為有效氧源;pH升高有利于催化活性;溫度升高有利于染料降解;-3-24-l、、NOSOC存在不影響染料的完全降解;-2-rNOB、存在,染料降解率只有80%左右,不能完全降解。選擇染料降解的最適條件:H_2O_2為氧源、(7)(8)(7)染料雙氧水(8)1:400n:n(28)、pH=9.1、T=40℃。3)以H_2O_2為氧源、n雙氧水:n染料=400:1、pH=9.1、T=40℃,催化劑用量為4mg/L(染料濃度30mg/L)條件下,考察了Cu-Schiffbase@SBA-15催化不同底物:甲基橙、羅丹明B、茜素紅、R、E、O、B等7種染料的降解效果。發(fā)現(xiàn)對于羅丹明B的降解效果最好,1.5hs可達到100%的降解率;對含硝基、溴等取代基團的染料R、E、O、B等降解效果較差,48h只有80%的降解率;說明催化劑Cu-Schiffbase@SBA-15具有一定的底物選擇性。4)考察了催化劑Cu-Schiffbase的構(gòu)效關(guān)系,發(fā)現(xiàn)鏈的延伸有利于催化活性,剛性增加使催化活性下降,給電子取代基能促進催化活性。5)考察了催化劑Cu-Schiff base的循環(huán)使用、機械穩(wěn)定性和酸堿穩(wěn)定性。發(fā)現(xiàn)5-6次循環(huán)后催化效果不變,N_2吸附類型不變,說明催化劑可循環(huán)使用,具有好的機械穩(wěn)定性。發(fā)現(xiàn)酸性條件下催化劑失活,加堿后可以恢復催化活性;在堿性條件下催化劑失活,加酸后催化活性不恢復,說明催化劑在酸到弱堿性條件下穩(wěn)定,在強堿性條件下結(jié)構(gòu)不穩(wěn)定。6)利用UV-vis、HPLC、CO_2的吸收實驗測定了降解產(chǎn)物,采用Mn法測定了降解前后的COD。發(fā)現(xiàn)苯環(huán)區(qū)吸收消失,降解產(chǎn)物有順丁烯二酸、草酸和CO_2,降解后COD為3-6.5mg/L。說明染料發(fā)生了降解,甚至達到礦化。7)利用Graph Pad Prism 5軟件對催化劑降解甲基橙進行了動力學模擬,發(fā)現(xiàn)催化劑對甲基橙的脫色降解具有酶學特性,符合Michaelis-Menten動力學模型規(guī)律。說明配合物固載后保留了仿酶活性。8)利用自由基捕捉實驗和自由基抑制實驗,發(fā)現(xiàn)水楊酸捕捉了羥基生成了2,5-二羥基苯甲酸,利用叔丁醇可以抑制染料的脫色降解,說明制備的催化劑在催化降解底物時的活性組分包括羥基自由基,并給出了可能的染料分子降解過程。
[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，
本文編號：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，
本文編號：2501393
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