發(fā)布時(shí)間：2018-04-29 06:26

  本文選題：鈀 + 鎳�。� 參考：《安徽大學(xué)》2015年碩士論文

【摘要】：貴金屬納米顆粒由于其優(yōu)異的催化性能而在許多重要的催化領(lǐng)域得到了廣泛的應(yīng)用。近年來很對課題組發(fā)現(xiàn)貴金屬鈀與其它貴金屬相比,穩(wěn)定性高,催化效果好,可以用于催化很多的有機(jī)反應(yīng)。更為重要的是,隨著合成方法的改進(jìn)和單晶衍射技術(shù)的發(fā)展,貴金屬(Pd,Pt,Au,Ag)與非貴金屬(Fe,Co,Ni,Cu等等)形成的合金納米材料已經(jīng)吸引了很多科學(xué)研究組對其形貌,結(jié)構(gòu),尺寸大小,組成以及催化性能進(jìn)行研究,但真正具有特殊形貌,尺寸均一,可回收循環(huán)利用的高效催化性能的催化劑還很有限。目前,最具代表性的催化體系是具有不同的幾何形態(tài)學(xué),電子結(jié)構(gòu)和協(xié)同效應(yīng)的雙金屬合金納米催化劑,已經(jīng)發(fā)現(xiàn)它們可作為高活性催化劑應(yīng)用于有機(jī)合成,電催化,傳感器和臨床診斷學(xué)方面。這類多功能催化劑由于協(xié)同效應(yīng)不僅具有單一成分金屬的性質(zhì)而且還具有多金屬的特殊催化性質(zhì)。利用摻雜了非貴金屬的特點(diǎn),減少了貴金屬的利用率,利用這種協(xié)同作用,提高了催化效率,利用這種可回收循環(huán)利用的性質(zhì),符合綠色化學(xué)的要求,是新一代理想的催化劑,是貴金屬納米催化領(lǐng)域的研究熱點(diǎn)。本文就在前人的研究基礎(chǔ)上,合成鈀系納米合金,應(yīng)用于催化有機(jī)反應(yīng),研究貴金屬納米合金催化劑的結(jié)構(gòu),形貌,組成以及催化活性。主要內(nèi)容如下：1.本文通過共還原的一步法有效合成一系列組分可控的鈀鎳納米合金,在這個(gè)合成過程中,油胺作為溶劑和還原劑,三苯基膦作為配體穩(wěn)定劑對于合成這樣一系列的單分散納米合金有著重要的作用。Pd-Ni合金具有均一的尺寸并且組成可通過改變前驅(qū)體的比例來調(diào)控。我們研究這些合金對于Miyauru-Heck反的催化活性,實(shí)驗(yàn)結(jié)果表明,合金比等量的Pd的催化效果好,并且Pd1Ni1在一系列的合金中催化效果最好。最重要的是,Pd-Ni合金同樣可以催化Heck反應(yīng)的一系列底物。2.本文采用一步法制備尺寸和形貌均一的球狀的鈀銀納米合金催化劑,并通過用X射線衍射儀(XRD)、透射電子顯微鏡(TEM)、高分辨電子顯微鏡(HRTEM)等對其結(jié)構(gòu)和形貌進(jìn)行表征。實(shí)驗(yàn)結(jié)果表明,通過改變溫度能夠很好地調(diào)控其形貌。在此基礎(chǔ)上,研究了Pd-Ag納米顆粒的有機(jī)催化性能。實(shí)驗(yàn)表明,當(dāng)Pd-Ag合金的形貌為均一的球形的時(shí)候,催化Suzuki偶聯(lián)反應(yīng)產(chǎn)率最高。
[Abstract]:Noble metal nanoparticles have been widely used in many important catalytic fields due to their excellent catalytic properties. In recent years, it has been found that palladium has higher stability and better catalytic effect than other precious metals, so it can be used to catalyze many organic reactions. More importantly, with the improvement of the synthesis method and the development of single crystal diffraction technique, the alloy nanomaterials formed by the noble metal PdPtPtAg-Ag and the non-precious metal FeCoCoNI-Cu) have attracted many scientific research groups on their morphology, structure, size, etc. The composition and catalytic performance of the catalyst were studied, but the catalyst with special morphology, uniform size and recyclable high performance catalyst is still very limited. At present, the most representative catalytic systems are bimetallic alloy nanocatalysts with different geometric morphology, electronic structure and synergistic effect. It has been found that they can be used as highly active catalysts for organic synthesis and electrocatalysis. Sensors and clinical diagnostics. Because of the synergistic effect, this kind of multifunctional catalysts have not only the properties of single component metals but also the special catalytic properties of polymetallic catalysts. The utilization rate of precious metals is reduced by doping non-precious metals, and the catalytic efficiency is improved by using this synergistic effect. The properties of recycling and recycling are in line with the requirements of green chemistry and are the new generation of ideal catalysts. It is a hotspot in the field of nanometer catalysis of noble metals. In this paper, palladium nanocrystalline alloys were synthesized on the basis of previous studies, and were used to catalyze organic reactions. The structure, morphology, composition and catalytic activity of noble metal nano-alloy catalysts were studied. The main content is as follows: 1. In this paper, a series of controllable palladium and nickel nanocrystalline alloys were synthesized by one step co-reduction method. In this process, oleamine was used as solvent and reducing agent. Triphenylphosphine as a ligand stabilizer plays an important role in the synthesis of such a series of monodisperse nanoalloys. Pd-Ni alloys have uniform size and their composition can be controlled by changing the proportion of precursors. We have studied the catalytic activity of these alloys for Miyauru-Heck inversion. The experimental results show that the catalytic activity of these alloys is better than that of the same amount of PD, and that of Pd1Ni1 is the best in a series of alloys. The most important is that Pd-Ni alloy can also catalyze a series of substrates of Heck reaction. In this paper, spherical palladium and silver nanocrystalline catalysts with uniform size and morphology were prepared by one-step method. The structure and morphology of the catalysts were characterized by X-ray diffractometer (XRD), transmission electron microscopy (TEM) and HRTEM (high resolution electron microscope). The experimental results show that the morphology can be well controlled by changing the temperature. On this basis, the organic catalytic properties of Pd-Ag nanoparticles were studied. The results show that the yield of catalytic Suzuki coupling reaction is the highest when the morphology of Pd-Ag alloy is uniform and spherical.
【學(xué)位授予單位】：安徽大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TB383.1;O643.36

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 周華,董守安;納米金負(fù)載型催化劑的研究進(jìn)展[J];貴金屬;2004年02期

，

本文編號：1818794