功能化石墨烯材料的制备及其在C-N偶联和Knoevenagel缩合反应中的应用

发布时间：2018-07-10 06:11

本文选题：功能化石墨烯 + 铜催化剂　；参考：《西华师范大学》2015年硕士论文

【摘要】：本文系统研究了功能化石墨烯材料在C-N偶联反应和Knoevenagel缩合反应中的应用,通过简单的化学方法制备了具有不同性能的石墨烯材料,利用不同的表征方法对各种石墨烯材料进行了详细分析,主要研究内容如下:首先,通过简单的原位化学还原制备出了铜石墨烯复合材料(Cu-r GO),利用傅里叶变换红外光谱(FT-IR)、X-射线单晶衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和X-射线光电子能谱(XPS)等手段对该复合材料进行了表征。结果表明,铜已经成功负载到了石墨烯表面,并且主要以二价形式存在。催化活性研究结果表明,Cu-rGO材料作为多相催化剂用于C-N偶联反应具有很好的催化活性,催化剂用量少,易分离循环。其次,利用L-氨基酸中氨基和氧化石墨烯(GO)上羧基之间的酰胺化反应对氧化石墨烯材料进行了改性,再通过原位化学还原制备了氨基酸石墨烯铜杂化材料(A-G-Cu),并对所有催化剂进行了详细的表征,包括原子力显微镜(AFM)和电感耦合等离子体原子发射光谱(ICP-AES)。结果表明,功能化后的石墨烯材料能够更好地固载金属纳米粒子,同时氨基酸对金属纳米粒子具有电子改性的作用。将该材料作为多相催化剂也用于C-N偶联反应中,结果表明,该催化剂具有比Cu-rGO催化剂更高的催化活性,修饰上的氨基酸和Cu NPs之间具有一定的协同催化作用。此外,系统研究了L-酪氨酸修饰的石墨烯铜催化剂(Tyr-G-Cu)在C-N偶联反应中的通用性和循环稳定性。最后,我们制备了两种碱性石墨烯材料,并研究了其催化Knoevenagel缩合反应的活性。一方面,通过丙二腈与GO上环氧官能团的加成反应制备了丙二腈功能化石墨烯,再原位还原获得了氨基石墨烯材料(G-NH2)。另一方面,采用碱性L-赖氨酸修饰氧化石墨烯制备了L-赖氨酸功能化石墨烯材料(Lys-GO)。通过CO2脱吸附证实,G-NH2和Lys-GO材料都具有一定的碱性,比较而言,Lys-GO的碱度更高,结果表明碱性氨基基团可以有效调节石墨烯的酸碱度。催化性能测试表明,两种材料都具有好的催化活性,其催化活性的大小与催化剂材料的碱度有关。
[Abstract]:The applications of functionalized graphene materials in C-N coupling reactions and Knoevenagel condensation reactions were systematically studied. Graphene materials with different properties were prepared by simple chemical method. Various graphene materials are analyzed in detail by different characterization methods. The main contents are as follows: firstly, Copper-graphene composites (Cu-r go) were prepared by simple in situ chemical reduction. Fourier transform infrared (FT-IR) X-ray single crystal diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) were used. The composite was characterized by other means. The results show that copper has been successfully loaded on the surface of graphene and mainly exists in the form of divalent. The results of catalytic activity study showed that Cu-rGO as a heterogeneous catalyst had a good catalytic activity for C-N coupling reaction, the amount of catalyst was less, and the separation cycle was easy. Secondly, graphene oxide materials were modified by amidation reaction between amino groups and carboxyl groups of graphene oxide (go) in L-amino acids. Amino acid graphene copper hybrid materials (A-G-Cu) were prepared by in situ chemical reduction. All the catalysts were characterized in detail, including atomic force microscopy (AFM) and inductively coupled plasma atomic emission spectrometry (ICP-AES). The results show that the functionalized graphene materials can better immobilize metal nanoparticles and amino acids have the effect of electronic modification on metal nanoparticles. The catalyst was also used as a heterogeneous catalyst for C-N coupling reaction. The results showed that the catalyst had higher catalytic activity than Cu-rGO catalyst, and there was a certain synergistic catalysis between amino acid and Cu NPs. In addition, the universality and cyclic stability of L-tyrosine modified graphene copper catalyst (Tyr-G-Cu) in C-N coupling reaction were systematically studied. Finally, we prepared two basic graphene materials and studied their catalytic activity for Knoevenagel condensation. On the one hand, the functionalized graphene was prepared by the addition reaction of malonitrile and epoxy functional group on go, and then in situ reduction was carried out to obtain the amino graphene material (G-NH2). On the other hand, L-lysine functionalized graphene (Lys-GO) was prepared by alkaline L-lysine modified graphene oxide. The results of CO _ 2 desorption show that both G-NH _ 2 and Lys-GO have certain alkalinity, and the alkalinity of Lys-GO is higher than that of Lys-GO. The results show that the basic amino group can effectively regulate the acidity of graphene. The results showed that both materials had good catalytic activity, and their catalytic activity was related to the alkalinity of the catalyst materials.
【学位授予单位】：西华师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O643.36;TQ127.11

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