本文選題：軸向配體 + 催化氧化　； 參考：《浙江理工大學(xué)》2016年碩士論文

【摘要】：環(huán)境水污染中酚類化合物是一種來源廣泛,難以降解,對自然環(huán)境有著巨大危害的有機(jī)污染廢水,是國內(nèi)外要求被嚴(yán)重控制的有機(jī)污染物之一。對傳統(tǒng)的高級氧化技術(shù),催化體系常常含有H2O2利用率低、對難降解的有機(jī)污染物催化活性差、催化劑難以重復(fù)使用等問題。因此開發(fā)一種高效綠色的去除廢水中有毒目標(biāo)污染物的催化體系具有重要意義。金屬酞菁類化合物與細(xì)胞色素P-450的活性中心金屬卟啉結(jié)構(gòu)相似,具有類似于生物酶的催化活性和選擇性,其催化過程是通過中心金屬離子與反應(yīng)物發(fā)生配位進(jìn)行的。碳納米管具有獨特的物理性質(zhì)和結(jié)構(gòu)、優(yōu)良的電化學(xué)性能、大的比表面積、較好的物理吸附能力以及在很多條件下均具有較高的穩(wěn)定性,決定了其可以作為非均相催化劑的理想載體材料。因此,可以將具有模擬酶催化劑的金屬酞菁負(fù)載到改性的碳納米管上,研究催化體系的催化性能,探索負(fù)載型催化劑的改善方法。本文利用兩種不同的配體(4-氨基吡啶(Py)和巰基乙胺(CS))改性碳納米管,分別使用脫氨基法和酰胺化方法改性碳納米管得到MWCNTs-Py和MWCNTs-CS,再通過軸向配位的思想制備合成兩種碳納米管軸向負(fù)載金屬酞菁催化劑(FePc-Py-MWCNTs, FePc-CS-MWCNTs)。采用UV-vis、XPS、FTIR等方法對催化劑進(jìn)行表征結(jié)果表明FePc成功地通過軸向配位的方式負(fù)載到碳納米管上。選用對氯苯酚(4-CP)作為目標(biāo)污染物,H2O2為氧化劑,研究催化劑的催化氧化能力。實驗結(jié)果表明：FePc-Py-MWCNTs/H2O2體系在酸性條件下相對于FePc/MWCNTs/H2O2體系具有較高的活性,說明配體的引入可以極大地改善催化體系的活性；FePc-CS-MWCNTs/H2O2體系相較與FePc-Py-MWCNTs/H2O2體系,無論是酸性條件還是中性條件都具有很好的催化活性,且催化劑的循環(huán)使用性要高得多。EPR測試兩個催化體系都有羥基自由基(·OH)和過氧自由基(·OOH)的存在,表明二者反應(yīng)都是一個羥基自由基為主導(dǎo)的反應(yīng),這與傳統(tǒng)的含有配體存在的催化體系由高價金屬主導(dǎo)的反應(yīng)不同。在本論文的催化體系中,由于軸向配體對中心金屬Fe的供電子效應(yīng)使得FeⅢ/Ⅱ的氧化電位更低,加快了在傳統(tǒng)Fenton反應(yīng)體系中FeⅢ向FeⅡ的轉(zhuǎn)化過程。本論文的研究提供了一種通過軸向配位的方法制備合成負(fù)載型催化劑,為催化劑的改善和催化體系的優(yōu)化設(shè)計奠定了一定的基礎(chǔ)。
[Abstract]:Phenolic compounds in environmental water pollution are one of the organic pollutants which are widely available and difficult to degrade and have great harm to the natural environment. They are one of the organic pollutants which are required to be seriously controlled at home and abroad. For the traditional advanced oxidation technology, the catalytic system often contains low utilization rate of H2O2, poor catalytic activity for refractory organic pollutants, and difficult to reuse the catalyst. Therefore, it is of great significance to develop an efficient green catalytic system for removing toxic target pollutants from wastewater. Metal phthalocyanines are similar to cytochrome P-450 in the structure of active center metalloporphyrins and have catalytic activity and selectivity similar to those of biological enzymes. The catalytic process of metal phthalocyanines is carried out by the coordination of central metal ions with reactants. Carbon nanotubes have unique physical properties and structure, excellent electrochemical performance, large specific surface area, good physical adsorption ability and high stability under many conditions. It is determined that it can be used as an ideal support material for heterogeneous catalysts. Therefore, the metal phthalocyanine with mimic enzyme catalyst can be loaded on the modified carbon nanotubes to study the catalytic performance of the catalyst system and explore the improvement methods of the supported catalyst. In this paper, two different ligands (4-aminopyridine) and mercaptoethylamine (CSA) were used to modify carbon nanotubes. MWCNTs-Py and MWCNTs-CSwere prepared by deamination method and amidation method respectively. Then two kinds of carbon nanotubes supported metal phthalocyanine catalysts FePc-Py-MWCNTsand FePc-CS-MWCNTswere synthesized by the idea of axial coordination. The characterization of the catalyst by UV-vis-XPS-FTIR showed that FePc was successfully loaded onto carbon nanotubes by axial coordination. The catalytic oxidation ability of the catalyst was studied by using p-chlorophenol 4-CP) as the target pollutant H _ 2O _ 2 as oxidant. The experimental results show that the FePc-Py-MWCNTsH _ 2O _ 2 / H _ 2O _ 2 system has higher activity than that of FePc/MWCNTs/H2O2 system in acidic condition, which indicates that the introduction of ligand can greatly improve the activity of FePc-CS-MWCNTs / H _ 2O _ 2 system compared with FePc-Py-MWCNTs/H2O2 system. Both acidic and neutral conditions had good catalytic activity, and the reusability of the catalysts was much higher. EPR showed that there were hydroxyl radical (OH) and peroxy radical (OOH) in both systems. It is shown that both reactions are dominated by hydroxyl radical, which is different from the traditional catalytic system containing ligand, which is dominated by high valence metal. In the catalytic system of this thesis, the oxidation potential of Fe 鈪，

本文編號：1935460