本文選題：貴金屬 + 鉑�。� 參考：《安徽大學(xué)》2017年碩士論文

【摘要】：貴金屬納米材料由于其在光學(xué)、力學(xué)、磁學(xué)、電學(xué)、催化和傳感等領(lǐng)域表現(xiàn)出優(yōu)異的物理和化學(xué)特性,受到了廣泛關(guān)注。然而,由于本身性質(zhì)方面的一些局限性以及十分稀少的儲(chǔ)量,在很大程度上限制了貴金屬納米材料大規(guī)模的應(yīng)用。因此,人們希望尋求一種策略,在改良貴金屬納米材料性質(zhì)的同時(shí)減少貴金屬的使用量。研究表明通過(guò)與其他金屬形成合金,能夠可控的合成特定尺寸、組成、形貌以及結(jié)構(gòu)構(gòu)架的金屬納米材料,并且明顯的改變其如光、電、磁、催化以及機(jī)械性質(zhì)等物理化學(xué)方面的性質(zhì)。因此,在近些年來(lái)人們對(duì)貴金屬合金納米材料的尺寸,組成,形貌以及架構(gòu)的可控合成方面進(jìn)行了深入的研究。合金中不同的金屬原子之間會(huì)產(chǎn)生相互的作用,形成特定的表面活性中心或電子結(jié)構(gòu)。因?yàn)閰f(xié)同效應(yīng)的存在,合金納米材料往往具有優(yōu)于其單一金屬納米材料的性質(zhì),同時(shí)貴金屬與非貴金屬形成合金也能夠減少貴金屬的使用降低成本費(fèi)用,這非常符合工業(yè)生產(chǎn)降低貴金屬使用量提高貴金屬利用率的趨勢(shì)。利用貴金屬催化劑催化非均相反應(yīng),其在穩(wěn)定性和循環(huán)利用方面良好的表現(xiàn),也非常符合綠色化學(xué)的理念。但是在貴金屬合金納米材料應(yīng)用到實(shí)際生產(chǎn)的過(guò)程中,依然面臨著許多挑戰(zhàn)。合成過(guò)程過(guò)于復(fù)雜、可控合成難以重復(fù)、催化機(jī)理不明確等等問題,激勵(lì)著科研工作者不斷的深入對(duì)貴金屬合金納米材料的研究。本文在前人的基礎(chǔ)上,合成了基于貴金屬Pt的合金納米材料,主要對(duì)其組成、尺寸、形貌以及催化活性進(jìn)行了一系列的探究:1.我們以油胺作為穩(wěn)定配體,甲基-胺硼烷絡(luò)合物作為還原劑,通過(guò)簡(jiǎn)單的方法合成了 AuPt合金納米顆粒。通過(guò)高分辨透射電子顯微鏡、X射線衍射、電感耦合等離子體發(fā)射光譜儀等儀器進(jìn)行表征。負(fù)載在CeO2上的AuPt合金納米材料在室溫常壓條件下選擇性催化氫化芐叉丙酮,表現(xiàn)出非常高的選擇性和催化效率。通過(guò)分析不同Au:Pt比組成的合金納米材料的催化表現(xiàn),我們發(fā)現(xiàn)基于Pt原子數(shù)計(jì)算的TONPt值的變化趨勢(shì)和轉(zhuǎn)化率的變化趨勢(shì)是非常相似的。盡管金本身在反應(yīng)中并不表現(xiàn)出催化活性,轉(zhuǎn)化率和TONPt的變化則清晰的反映出金對(duì)鉑的催化活性的促進(jìn)效應(yīng)。在我們的實(shí)驗(yàn)中,非活性金屬改良了活性金屬的催化活性,顯示了一種十分有意義的協(xié)同效應(yīng)。2.Pt合金納米材料因?yàn)槠鋬?yōu)異的性質(zhì),被廣泛的應(yīng)用在催化等領(lǐng)域。本文以油胺為保護(hù)劑配體和還原劑,在氮?dú)獗Ｗo(hù)下高溫合成PtCu合金納米顆粒,并且在空氣中攪拌使空氣中的氧氣氧化合金中暴露在表面的Cu變?yōu)殂~離子而脫離合金表面,得到具有花瓣?duì)钔黄鸾Y(jié)構(gòu)的PtCu合金納米材料。實(shí)驗(yàn)表明,PtCu合金具有較均一的尺寸和形貌,并在催化氫化肉桂醛的反應(yīng)中,表現(xiàn)出了良好的催化活性和選擇性。
[Abstract]:Noble metal nanomaterials have attracted much attention for their excellent physical and chemical properties in optical, mechanical, magnetic, electrical, catalytic and sensing fields. However, due to some limitations of its own properties and very scarce reserves, the large-scale application of noble metal nanomaterials is limited to a great extent. Therefore, we hope to find a strategy to improve the properties of noble metal nanomaterials while reducing the use of precious metals. Studies have shown that by forming alloys with other metals, metal nanomaterials of specific size, composition, morphology, and structure can be synthesized in a controllable manner, and that they can be changed significantly, such as light, electricity, magnetism, etc. The physical and chemical properties of catalysis and mechanical properties. Therefore, in recent years, the size, composition, morphology and structure of noble metal alloy nanomaterials have been studied in detail. Different metal atoms in the alloy interact with each other to form specific surface active centers or electronic structures. Because of the synergistic effect, alloy nanomaterials tend to have better properties than their single metallic nanomaterials, and the formation of alloys between noble metals and non-precious metals can also reduce the use of precious metals and reduce costs. This is in line with industrial production to reduce the amount of precious metals used to improve the utilization rate of precious metals. The heterogeneous reaction catalyzed by noble metal catalyst has good stability and recycling performance, and it also accords with the idea of green chemistry. However, there are still many challenges in the application of noble metal alloy nanomaterials to practical production. The synthesis process is too complex, the controllable synthesis is difficult to repeat, and the catalytic mechanism is unclear, which encourages researchers to study the noble metal alloy nanomaterials in depth. In this paper, based on the previous studies, the alloy nanomaterials based on noble metal Pt have been synthesized. The composition, size, morphology and catalytic activity of the alloy nanomaterials have been investigated in a series of ways: 1. AuPt alloy nanoparticles were synthesized by a simple method using oleamine as a stable ligand and methylamine borane complex as reducing agent. It was characterized by high resolution transmission electron microscope (TEM) and inductively coupled plasma emission spectrometer (ICP-AES). The AuPt alloy nanomaterials supported on CeO2 can selectively catalyze the hydrogenation of benzylidene acetone at room temperature and atmospheric pressure, showing very high selectivity and catalytic efficiency. By analyzing the catalytic performance of alloy nanomaterials with different Au:Pt ratios, we find that the change trend of TONPt value and conversion rate based on Pt atom number is very similar. Although gold itself does not exhibit catalytic activity in the reaction, the changes in conversion and TONPt clearly reflect the catalytic effect of gold on platinum activity. In our experiments, inactive metals have improved the catalytic activity of active metals, showing a significant synergistic effect .2. Pt alloy nanomaterials have been widely used in catalysis and other fields because of their excellent properties. In this paper, PtCu alloy nanoparticles were synthesized at high temperature under nitrogen protection with oleamine as protective ligands and reductants. The Cu exposed to the surface of oxygen oxidized alloy in air was changed into copper ion and separated from the surface of the alloy by stirring in air. PtCu alloy nanomaterials with petal-like protruding structure were obtained. The results show that the PtCu alloy has a uniform size and morphology, and shows good catalytic activity and selectivity in the catalytic hydrogenation of cinnamaldehyde.
【學(xué)位授予單位】：安徽大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TB383.1;O643.36

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本文編號(hào)：1875635