納米鎳鈷的制備及其應(yīng)用于酮酸酯電催化不對稱加氫的研究
發(fā)布時間：2019-01-03 15:57
【摘要】：不對稱催化合成作為制備手性化合物的一種重要手段,已經(jīng)得到越來越多科研工作者的關(guān)注,并且取得了眾多的科研成果。其中,催化劑作為不對稱催化合成反應(yīng)的重要反應(yīng)媒介,尤其受到人們的重視,金屬催化劑是其中重要的一類。大多數(shù)不對稱金屬催化劑均為Pt、Pd等鉑族貴金屬,然而這類貴金屬的全球儲量有限,并且還在貴重飾品、高新材料等領(lǐng)域有著重大需求。因此,開發(fā)非貴金屬不對稱催化劑有著重要的研究價值。電化學合成作為一門綠色合成技術(shù)有著眾多優(yōu)點,逐漸得到人們的青睞,特別是已經(jīng)出現(xiàn)了一些利用電化學方法制備手性化合物的科學研究。本論文主要從上面兩點出發(fā),研究非貴金屬Ni、Co納米材料的制備及其應(yīng)用于酮酸酯類化合物電催化不對稱加氫的效果。具體實驗研究如下:(1)納米鎳的制備及其應(yīng)用于酮酸酯電催化不對稱加氫的研究利用液相化學還原法制備納米鎳材料,用XRD、SEM等方法表征合成的納米鎳,并將其壓成圓片以作工作電極。在一室型電解池中,以制備的納米鎳為工作電極,分別以生物堿和酒石酸為手性誘導劑,H2O為氫源,研究納米鎳電催化苯甲酰甲酸乙酯和苯甲酰乙酸乙酯兩種酮酸酯不對稱加氫的效果。分別用GC-MS對產(chǎn)物定性分析,HPLC對產(chǎn)物進行定量分析。考察了電解電量,溶劑配比,電流密度,反應(yīng)溫度等對反應(yīng)的影響;并考察了兩底物在納米鎳電極上的循環(huán)伏安行為。實驗結(jié)果證明納米鎳應(yīng)用于羰基化合物電催化不對稱加氫的思路行之有效。(2)TA@Ni/Co手性雙金屬納米材料的制備及其應(yīng)用于α酮酸酯電催化不對稱加氫的研究在制備納米鎳材料的基礎(chǔ)上,將相應(yīng)的液相還原條件加以改進,以Ni鹽和Co鹽摩爾比為1:1制備Ni/Co納米雙金屬,再利用酒石酸和Ni、Co等金屬較強的相互作用,將手性酒石酸修飾到Ni/Co納米材料中,制備出TA@Ni/Co手性雙金屬納米材料。用XRD、SEM、ICP、FT-IR等方法表征合成的材料。將TA@Ni/Co手性雙金屬納米材料修飾于碳紙表面,作工作電極。在一室型電解池中,以醇類為氫源,研究手性雙金屬納米材料電催化苯甲酰甲酸乙酯和苯甲酰甲酸甲酯兩種α酮酸酯不對稱加氫合成的效果。同樣考察了苯甲酰甲酸乙酯在手性雙金屬電極上的循環(huán)伏安行為。實驗結(jié)果顯示,以TA@Ni/Co手性納米雙金屬為工作電極相較于以單金屬納米鎳為工作電極,電解產(chǎn)物在保有一定ee值的基礎(chǔ)上,產(chǎn)率提升相當高。
[Abstract]:Asymmetric catalytic synthesis as an important method for the preparation of chiral compounds has been paid more and more attention by researchers and many scientific achievements have been obtained. As an important reaction medium of asymmetric catalytic synthesis, catalysts have been paid more and more attention, among which metal catalysts are one of the most important ones. Most asymmetric metal catalysts are platinum group precious metals such as Pt,Pd. However, the global reserves of these precious metals are limited, and there is a great demand in such fields as precious ornaments, high-tech materials and so on. Therefore, the development of non-noble metal asymmetric catalysts has important research value. Electrochemical synthesis as a green synthesis technology has many advantages, and has been gradually favored by people. Especially, there have been some scientific research on the preparation of chiral compounds by electrochemical methods. In this paper, the preparation of non-precious metal Ni,Co nanomaterials and its application in asymmetric hydrogenation of ketoacid esters were studied from the above two points. The experimental results are as follows: (1) preparation of nano-nickel and its application in asymmetric hydrogenation of ketoate; Nano-nickel was prepared by liquid-phase chemical reduction method and characterized by XRD,SEM method. It is pressed into a disk to serve as a working electrode. In a one-chamber electrolytic cell, the prepared nano-nickel was used as working electrode, alkaloids and tartaric acid as chiral inducers and H2O as hydrogen source, respectively. The asymmetric hydrogenation of ethyl benzoyl formate and ethyl benzoyl acetate catalyzed by nanometer nickel was studied. GC-MS and HPLC were used for qualitative analysis and quantitative analysis respectively. The effects of electrolysis, solvent ratio, current density and reaction temperature on the reaction were investigated, and the cyclic voltammetry of the two substrates on the nanocrystalline nickel electrode was investigated. The experimental results show that the application of nano-nickel in asymmetric hydrogenation of carbonyl compounds is effective. (2) preparation of TA@Ni/Co chiral bimetallic nanomaterials and their application in asymmetric hydrogenation of 偽 ketoate Based on the preparation of nanocrystalline nickel, The corresponding liquid phase reduction conditions were improved to prepare Ni/Co nano-bimetallic at 1:1 with the molar ratio of Ni salt and Co salt as 1:1. The strong interaction between tartaric acid and Ni,Co and other metals was used. Chiral tartaric acid was modified into Ni/Co nanomaterials to prepare TA@Ni/Co chiral bimetallic nanomaterials. The synthesized materials were characterized by XRD,SEM,ICP,FT-IR and other methods. TA@Ni/Co chiral bimetallic nanomaterials were modified on the surface of carbon paper and used as working electrode. The asymmetric hydrogenation of ethyl benzoate and methyl benzoate was studied in a one-chamber electrolytic cell using alcohol as hydrogen source and chiral bimetallic nanomaterials as catalyst. The cyclic voltammetry of ethyl benzoate on chiral bimetallic electrode was also investigated. The experimental results show that the yield of electrolysis products with TA@Ni/Co chiral nanometer bimetallic as working electrode is higher than that with single metal nanocrystalline nickel on the basis of keeping a certain ee value.
【學位授予單位】：華東師范大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：O621.251
本文編號：2399588
[Abstract]:Asymmetric catalytic synthesis as an important method for the preparation of chiral compounds has been paid more and more attention by researchers and many scientific achievements have been obtained. As an important reaction medium of asymmetric catalytic synthesis, catalysts have been paid more and more attention, among which metal catalysts are one of the most important ones. Most asymmetric metal catalysts are platinum group precious metals such as Pt,Pd. However, the global reserves of these precious metals are limited, and there is a great demand in such fields as precious ornaments, high-tech materials and so on. Therefore, the development of non-noble metal asymmetric catalysts has important research value. Electrochemical synthesis as a green synthesis technology has many advantages, and has been gradually favored by people. Especially, there have been some scientific research on the preparation of chiral compounds by electrochemical methods. In this paper, the preparation of non-precious metal Ni,Co nanomaterials and its application in asymmetric hydrogenation of ketoacid esters were studied from the above two points. The experimental results are as follows: (1) preparation of nano-nickel and its application in asymmetric hydrogenation of ketoate; Nano-nickel was prepared by liquid-phase chemical reduction method and characterized by XRD,SEM method. It is pressed into a disk to serve as a working electrode. In a one-chamber electrolytic cell, the prepared nano-nickel was used as working electrode, alkaloids and tartaric acid as chiral inducers and H2O as hydrogen source, respectively. The asymmetric hydrogenation of ethyl benzoyl formate and ethyl benzoyl acetate catalyzed by nanometer nickel was studied. GC-MS and HPLC were used for qualitative analysis and quantitative analysis respectively. The effects of electrolysis, solvent ratio, current density and reaction temperature on the reaction were investigated, and the cyclic voltammetry of the two substrates on the nanocrystalline nickel electrode was investigated. The experimental results show that the application of nano-nickel in asymmetric hydrogenation of carbonyl compounds is effective. (2) preparation of TA@Ni/Co chiral bimetallic nanomaterials and their application in asymmetric hydrogenation of 偽 ketoate Based on the preparation of nanocrystalline nickel, The corresponding liquid phase reduction conditions were improved to prepare Ni/Co nano-bimetallic at 1:1 with the molar ratio of Ni salt and Co salt as 1:1. The strong interaction between tartaric acid and Ni,Co and other metals was used. Chiral tartaric acid was modified into Ni/Co nanomaterials to prepare TA@Ni/Co chiral bimetallic nanomaterials. The synthesized materials were characterized by XRD,SEM,ICP,FT-IR and other methods. TA@Ni/Co chiral bimetallic nanomaterials were modified on the surface of carbon paper and used as working electrode. The asymmetric hydrogenation of ethyl benzoate and methyl benzoate was studied in a one-chamber electrolytic cell using alcohol as hydrogen source and chiral bimetallic nanomaterials as catalyst. The cyclic voltammetry of ethyl benzoate on chiral bimetallic electrode was also investigated. The experimental results show that the yield of electrolysis products with TA@Ni/Co chiral nanometer bimetallic as working electrode is higher than that with single metal nanocrystalline nickel on the basis of keeping a certain ee value.
【學位授予單位】：華東師范大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：O621.251
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相關(guān)期刊論文 前2條
1 傅小明;;納米鎳的物理法制備技術(shù)及研究現(xiàn)狀[J];湖南有色金屬;2010年03期
2 許錫恩，王志峰，，田松江;手性金屬絡(luò)合物催化劑的制備和應(yīng)用[J];石油化工;1996年02期
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