本文選題：多金屬氧酸鹽　切入點：雜多藍　出處：《揚州大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：多金屬氧酸鹽是一類金屬氧簇?zé)o機化合物,其結(jié)構(gòu)穩(wěn)定,熱穩(wěn)定性好,反應(yīng)條件溫和,既具有酸催化性能,又具有氧化還原催化性能,且催化的反應(yīng)活性高,選擇性好,是高效的環(huán)境友好型的綠色雙功能催化劑。它無論是在均相還是多相催化反應(yīng)中都擁有良好的催化活性,在很多領(lǐng)域有著廣泛的應(yīng)用。本文中我們分別從三個不同的方面探究多金屬氧酸鹽的催化性能,主要研究內(nèi)容和結(jié)論如下:1.以 Well-Dawson 磷鎢酸 H6[P2W18062]·24H20(oxi-[P2W18062]6-)作為母體采用化學(xué)還原的方法制備兩種雜多藍晶體:H10[P2W18O62]·27H2O(red-[P2W18O62]10-),H7[P2W18062]·12H2O(int-[P2W18062]7-)。通過單晶X-射線衍射、紅外光譜、拉曼光譜、紫外光譜、循環(huán)伏安、熱重分析、光電子能譜等對其結(jié)構(gòu)進行基礎(chǔ)表征。將雜多藍晶體red-[P2W18062]10-負(fù)載到氧化石墨烯表面,利用red-[P2W18062]10-的還原性還原氧化石墨烯,同時硝酸銀被還原成銀納米粒子負(fù)載到氧化石墨烯表面,制備出rGO@P2W18@Ag復(fù)合材料催化劑,這一過程中red-[P2W18062]10-失去電子變成oxi-[P2W18062]6-。同時探究復(fù)合材料催化劑對硼氫化鈉還原對硝基苯酚的催化性能以及催化機理,結(jié)果表明oxi-[P2W18062]6-作為“電子海綿”儲存電子協(xié)同銀納米粒子的催化作用在50秒內(nèi)使對硝基苯酚被硼氫化鈉還原成對氨基苯酚。2.我們采用一步法將Zn2+作為一種低成本和環(huán)保的控制劑來改性前驅(qū)體[B-α-BiW9033]9-。在硫酸鋅存在下,由前驅(qū)體Na9[BiW9O33]·16H20制備新型二維聚合物Zn/Bi-多金屬氧酸鹽Na2Zn4H5[Zn3Bi(B-α-ZnW9034)2]52H20。我們對制備成功的Zn/Bi夾心型鎢酸鹽分別進行了 X-射線分析,FT-IR、Raman、UV、熱重分析(TG)、CV等一系列表征證明其結(jié)構(gòu)和性質(zhì)。以過氧化氫氧化環(huán)已醇生成環(huán)已酮為研究對象,作為均相催化劑研究其催化活性及催化活性位點。3.我們以TEOS作為前驅(qū)體對Fe3O4納米粒子的表面進行改性,制備了 Fe3O4@Si02磁性顆粒。通過陰陽離子的靜電作用將擁有良好磁學(xué)性質(zhì)的磁性納米粒子和雜多酸相結(jié)合制備出負(fù)載型的磁性雜多酸催化劑。同樣的以過氧化氫氧化環(huán)已醇生成環(huán)已酮為研究對象,在外加磁場的環(huán)境中能夠?qū)崿F(xiàn)催化劑簡單高效的分離,解決了雜多酸在催化過程中易溶解于反應(yīng)體系,較難實現(xiàn)催化劑的回收和再利用問題。
[Abstract]:Polyoxometalates are a kind of inorganic compounds with stable structure, good thermal stability and mild reaction conditions. They not only have acid catalytic activity, but also have redox catalytic activity, and the catalytic activity is high and the selectivity is good. It is a highly efficient environment-friendly green bifunctional catalyst. It has good catalytic activity in both homogeneous and heterogeneous catalytic reactions. In this paper, we explore the catalytic properties of polyoxometalates from three different aspects. The main contents and conclusions are as follows: 1. Two kinds of heteropoly blue crystals: H10 [P2W18O62] 路27H2O red- [P2W18O62] 10-H7 [P2W18062] 路12 H _ 2O _ int- [P2W18062] 7-H7 were prepared by chemical reduction method using Well-Dawson phosphotungstate H6 [P2W18062] 路24H20oxi- [P2W18062] 6-. by single crystal X-ray diffraction, infrared spectrum, Raman spectrum, UV spectrum, cyclic voltammetry, The structure was characterized by thermogravimetric analysis and photoelectron spectroscopy. The heteropoly blue crystal red- [P2W18062] 10- was loaded on the surface of graphene oxide, and the reductive reductive graphene was obtained by red- [P2W18062] 10-. At the same time silver nitrate was reduced to silver nanoparticles supported on the surface of graphene oxide to prepare rGO@P2W18@Ag composite catalyst. In this process, red- [P2W18062] 10- lost electrons became oxi- [P2W18062] 6-.At the same time, the catalytic properties and mechanism of composite catalyst for reduction of p-nitrophenol by sodium borohydride were investigated. The results show that oxi- [P2W18062] 6- acts as a "electron sponge" to store electrons in the presence of silver nanoparticles to reduce p-nitrophenol to p-aminophenol by sodium borohydride within 50 seconds. We used one-step method to treat Zn2 as a kind of low cost and low cost, and the results show that oxi- [P2W18062] 6- can reduce p-nitrophenol to p-aminophenol by sodium borohydride within 50 seconds. Environmental protection control agent to modify precursor [B- 偽 -BiW9033] 9-. in the presence of zinc sulfate, A novel two-dimensional polymer Na2Zn4H5 [Zn3BiB- 偽 -ZnW9034K2] 52H20was prepared from the precursor Na9 [BiW9O33] 路16H20. The structure and properties of the successfully prepared Zn/Bi sandwich tungstate were characterized by X-ray analysis and thermogravimetric analysis. Hydrogen peroxide oxidation of cyclohexanol to cyclohexanone was studied. As homogeneous catalyst, the catalytic activity and catalytic activity site of Fe3O4 nanoparticles were studied. 3. We used TEOS as precursor to modify the surface of Fe3O4 nanoparticles. Fe3O4@Si02 magnetic particles were prepared. Magnetic nanoparticles with good magnetic properties were combined with heteropoly acids by electrostatic interaction of anion and anion to prepare supported magnetic heteropoly acid catalyst. Similarly, hydrogen peroxide was used to oxidize the catalyst. Cyclohexanone was produced by cyclohexanol. In the environment of external magnetic field, the catalyst can be separated simply and efficiently, which solves the problem that heteropoly acid is easily dissolved in the reaction system in the process of catalysis, and it is difficult to realize the recovery and reuse of the catalyst.
【學(xué)位授予單位】：揚州大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：O643.36

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相關(guān)碩士學(xué)位論文 前1條

1 邢燁;雜多酸催化有機反應(yīng)的研究[D];新疆大學(xué);2008年

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本文編號：1623404