可见光下负载型CuPd合金纳米颗粒光催化Suzuki偶联反应

发布时间：2018-04-05 00:36

本文选题：可见光催化　切入点：载体　出处：《山西师范大学》2017年硕士论文

【摘要】：目前,将太阳能转化为化学能是一个非常热门的研究领域,因为它可以同时解决能源和环境问题。光催化技术在绿色化学领域有着非常大的发展前景,关于光催化的研究已经持续了几十年并仍在继续进行着。当前光催化技术的应用主要在分解水、环境治理以及有机合成等方面。本论文就光催化技术在有机合成领域的应用做一些研究。我们合成了一系列负载型CuPd合金纳米颗粒光催化剂,并将其应用于可见光常温催化Suzuki偶联反应,以此来对催化剂的光催化活性进行评价。我们的研究内容和成果包含以下几个方面:1)我们制备了g-C_3N_4和C两种催化剂载体,通过还原-浸渍的方法制备出分别以TiO2、ZrO2、g-C_3N_4、C负载的铜钯合金纳米颗粒以及以TiO2为载体的铜钯比例不同的负载型CuPd合金纳米颗粒。2)我们对所制备的负载型CuPd合金纳米颗粒进行了一系列表征,包括X射线能谱(EDS),透射电子显微镜(TEM),X射线光电子能谱(XPS),紫外可见吸收光谱(UV-Vis)。结果表明,我们所制得的负载型CuPd合金纳米颗粒确实形成了合金结构。3)我们选取了Suzuki偶联反应来测试催化剂的光催化活性。选取了对溴苯甲醚和苯硼酸作为模板反应物,并进一步对反应条件,包括溶剂、反应物浓度、反应物投料比、反应时间、碱的使用以及反应气氛等条件进行了优化。4)通过测试光催化剂在不同入射光光强及波长条件下的光催化活性,我们发现当我们提高入射光光强或者使用更短波长的入射光作为光源时,负载型CuPd合金纳米颗粒的光催化活性增强,也就是说光催化活性是由入射光的光强和波长决定的,这种情况说明了我们检测到的负载型CuPd合金纳米颗粒的光催化活性是由催化剂吸收光产生的高能激发电子引起的。5)为了测试光催化剂的适用范围,我们对含不同电子性质的取代基的反应物分子进行了光催化实验。结果表明了我们制备的负载型CuPd合金纳米颗粒对除氯苯外的大部分卤代芳烃都具有高效的光催化活性。6)我们对负载型CuPd合金纳米颗粒催化Suzuki偶联的重复使用进行了测试,发现在4次光催化循环之后,催化剂仍保持着较高的活性(转化率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%).
【学位授予单位】：山西师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O621.251

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