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可見光下負載型CuPd合金納米顆粒光催化Suzuki偶聯(lián)反應(yīng)

發(fā)布時間:2018-04-05 00:36

  本文選題:可見光催化 切入點:載體 出處:《山西師范大學》2017年碩士論文


【摘要】:目前,將太陽能轉(zhuǎn)化為化學能是一個非常熱門的研究領(lǐng)域,因為它可以同時解決能源和環(huán)境問題。光催化技術(shù)在綠色化學領(lǐng)域有著非常大的發(fā)展前景,關(guān)于光催化的研究已經(jīng)持續(xù)了幾十年并仍在繼續(xù)進行著。當前光催化技術(shù)的應(yīng)用主要在分解水、環(huán)境治理以及有機合成等方面。本論文就光催化技術(shù)在有機合成領(lǐng)域的應(yīng)用做一些研究。我們合成了一系列負載型CuPd合金納米顆粒光催化劑,并將其應(yīng)用于可見光常溫催化Suzuki偶聯(lián)反應(yīng),以此來對催化劑的光催化活性進行評價。我們的研究內(nèi)容和成果包含以下幾個方面:1)我們制備了g-C_3N_4和C兩種催化劑載體,通過還原-浸漬的方法制備出分別以TiO2、ZrO2、g-C_3N_4、C負載的銅鈀合金納米顆粒以及以TiO2為載體的銅鈀比例不同的負載型CuPd合金納米顆粒。2)我們對所制備的負載型CuPd合金納米顆粒進行了一系列表征,包括X射線能譜(EDS),透射電子顯微鏡(TEM),X射線光電子能譜(XPS),紫外可見吸收光譜(UV-Vis)。結(jié)果表明,我們所制得的負載型CuPd合金納米顆粒確實形成了合金結(jié)構(gòu)。3)我們選取了Suzuki偶聯(lián)反應(yīng)來測試催化劑的光催化活性。選取了對溴苯甲醚和苯硼酸作為模板反應(yīng)物,并進一步對反應(yīng)條件,包括溶劑、反應(yīng)物濃度、反應(yīng)物投料比、反應(yīng)時間、堿的使用以及反應(yīng)氣氛等條件進行了優(yōu)化。4)通過測試光催化劑在不同入射光光強及波長條件下的光催化活性,我們發(fā)現(xiàn)當我們提高入射光光強或者使用更短波長的入射光作為光源時,負載型CuPd合金納米顆粒的光催化活性增強,也就是說光催化活性是由入射光的光強和波長決定的,這種情況說明了我們檢測到的負載型CuPd合金納米顆粒的光催化活性是由催化劑吸收光產(chǎn)生的高能激發(fā)電子引起的。5)為了測試光催化劑的適用范圍,我們對含不同電子性質(zhì)的取代基的反應(yīng)物分子進行了光催化實驗。結(jié)果表明了我們制備的負載型CuPd合金納米顆粒對除氯苯外的大部分鹵代芳烴都具有高效的光催化活性。6)我們對負載型CuPd合金納米顆粒催化Suzuki偶聯(lián)的重復(fù)使用進行了測試,發(fā)現(xiàn)在4次光催化循環(huán)之后,催化劑仍保持著較高的活性(轉(zhuǎn)化率97%)。
[Abstract]:Currently, converting solar energy into chemical energy is a very hot research area because it can solve both energy and environmental problems.Photocatalytic technology has a great prospect in the field of green chemistry. The research on photocatalysis has been going on for several decades and is still going on.The current application of photocatalytic technology is mainly in water decomposition, environmental treatment and organic synthesis.In this paper, the application of photocatalysis in the field of organic synthesis has been studied.A series of supported CuPd alloy nanoparticles photocatalysts were synthesized and applied to the Suzuki coupling reaction under visible light at room temperature to evaluate the photocatalytic activity of the catalysts.Our research contents and results include the following aspects: 1) We have prepared two kinds of catalyst carriers, g-C_3N_4 and C,The copper-palladium alloy nanoparticles supported on TiO2OZrO2g-C3N4C and supported on TiO2 were prepared by reduction-impregnation method.The particles were characterized in a series of ways.It includes X-ray energy spectrum (EDS), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), UV-Visn (UV-Visn).The results show that the supported CuPd alloy nanoparticles formed the alloy structure. 3) We selected the Suzuki coupling reaction to test the photocatalytic activity of the catalyst.P-bromophenyl methyl ether and phenylboric acid were selected as template reactants, and the reaction conditions, including solvent, reactant concentration, reactant feed ratio, reaction time,The use of alkali and the reaction atmosphere were optimized. 4) the photocatalytic activity of the photocatalyst under different incident light intensity and wavelength was tested.We find that when we increase the intensity of incident light or use a shorter wavelength of incident light as a light source, the photocatalytic activity of the supported CuPd alloy nanoparticles increases, that is, the photocatalytic activity is determined by the intensity and wavelength of the incident light.This shows that the photocatalytic activity of the supported CuPd alloy nanoparticles we detected was caused by the high energy excited electrons generated by the catalyst absorbing light) in order to test the applicable range of photocatalysts,Photocatalytic experiments have been carried out on reactants with different electron properties.The results show that the supported CuPd alloy nanoparticles have high photocatalytic activity for most halogenated aromatics except chlorobenzene.It was found that after four photocatalytic cycles, the catalyst remained high activity (conversion rate 97%).
【學位授予單位】:山西師范大學
【學位級別】:碩士
【學位授予年份】:2017
【分類號】:O621.251

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