近年来有机电解合成的进展

在有机电解合成中采用反应性金属电极近年来已成为这一领域的新分支。这种类型的电极不仅起着在反应基质间进行电子交换的作用，而且也作为反应物参与反应，集电解合成与化学合成于一体。本文介绍借此方法一步合成醇，醛，酮羧酸等有机化合物的反应，讨论了电极性质及催化剂等因素对反应的影响，介绍有关电解合成装置。     

2，3－二甲基－2，3－丁二醇的电化学合成

介绍用丙酮电解还原合成频那醇的方法。电解合成反应可以在碱性介质或酸性介质条件下进行。并对不同电极、温度和电流密度对反应电流效率影响进行了研究。     

有机电化学的新进展

综述了有机电化学的最新进展。例如 :利用反应性电极的有机电合成 ;使用第Ⅳ族元素的有机电化学 ;利用三价磷化合物的有机电合成 ;把卤素作为成键元素的有机电合成 ;用光和磁场来影响电解反应的有机电合成等。     

2,3—甲基—2,3—丁二醇的电化学合成

介绍用丙酮电解还原合成频那醇的方法。电解合成可以在碱性介质或酸性介质条件下进行。并对不同电极、温度和电流密度对反应电流效率影响进行了研究。     

有机电解合成技术与应用

有阐述有机电解合成反应基本原理的基础上，讨论了几种有机电解合成方法与技术及其应用。     

工业有机电解合成工艺

一、绪言自1845年柯尔贝(Kolbc)反应以来,有机电解合成的历史已有100多年了。但是把电化学反应作为有机合成的手段还是不久的事.本世纪50年代由于离子交换膜技术的发展和电极反应技术的进展,到60年代中期,美国孟山都公司(Monsanto Co.)把已二腈的电解合成工艺和纳尔科公司(Nalco Co.)把四乙基铅的电解合成工艺大规模工业化,大型的     

电催化和粒子群电极用于处理有机工业污水

电化学方法处理含有机污染物的污水已引起广泛的兴趣。在电催化电极的作用下,电化学反应和化学催化作用结合,导致有机分子的电催化降解。由于粒子群电极可以提高电解效率,所以近年来受到相当的关注。选用合适的电极材料和采用粒子群电极可以加速电化学反应速率和增进电化学对催化作用的促进作用,因而在有机污水处理中它们将有助于有机物的电化学转化反应。其中论述了两个重要的问题,电极材料选择的科学依据和粒子群电极的应用前     

有机硅化合物的电解合成和电极反应

本文主要介绍有机硅化合物的电解合成和电极反应的几种方法及其生成物。     

有机试剂的电解合成

有机电解合成有很多优点。如: 1.电解条件合适时收率高、选择性好。 2.能量的利用率高。 3.由于电极的电子转移是电解合成的主要过程,因此在反应体系中除原料和生成物以外,往往不含其它的反应物。所以产物容易分离和精制,产品的纯度高。而且一般不需要废物处理设备。     

间接有机电解合成

间接有机电解合成是由基质以外的第二种物质与电极发生电子转移,然后在溶液中此第二种物质再与基质进行电子转移发生反应得到产物。而反应后此第二种物质又返回电极进行电子转移,如此反复循环制得产品。这里所用的第二种物质是在电极和基质之间     

Electrocatalytic oxidation of benzyl alcohol in alkaline medium on RuO2-coated titanium electrode

The heterogeneous electrocatalytic redox behaviour of RuO₂ electrodes fabricated by thermal decomposition is investigated with and without benzyl alcohol using cyclic voltammetric and potentiodynamic techniques. The cyclic voltammetric results show that benzyl alcohol oxidation is mediated by perruthenate ion electrogenerated at the electrode surface. Evaluation of kinetic parameters in relation to Tafel lines allows the postulation of a plausible reaction scheme in which benzyl alcohol adsorbs on the RuO₂ electrode surface and the rate determining step is chemical reaction between perruthenate and adsorbed species. The reaction orders with respect to benzyl alcohol and OH^– concentrations are 0.85 and 1, respectively. The results in galvanostatic electrolysis show that the major product for benzyl alcohol oxidation in an aqueous solution is benzaldehyde, and the organic yield is affected by such electrolysis conditions as t-butanol concentration, electrolysis current density, KOH concentration and electrolysis temperature.     

催化铁内电解法处理印染废水的研究

利用催化铁内电解法对酸性品红模拟印染废水进行处理,采用循环伏安法评价了酸性品红在铜电极和石墨电极上的电化学特性,结果表明催化铁内电解法与传统铁炭内电解法降解污染物的反应机理不同,通过对比发现,催化铁内电解法可以明显改善铁炭内电解法在碱性条件下的处理效果。单因素实验结果表明,进水pH为3,反应时间为1.5 h,铁铜质量比为6,不加入电解质时,对144 mg/L酸性品红模拟废水去除率能达到97.7%。废水中存在电解质时,可提高处理效果,去除率能达到99.5%;废水中加入过量铁铜填料对处理效果的改善并不明显。     

Einsatz perfluorierter Kationenaustauscher-Membranen in Elektroyseverfahren,insbesondere bei der Chloralkali-Elektrolyse

Use of perfluorinated cation exchanger membranes in electrolysis processes, particularly in alkali chloride electrolysis . Depending upon their structure, texture, and possible after-treatment, the properties of perfluorinated cation exchanger membranes show variations and their use has consequently been limited to electrolyses in aqueous solutions and indirect organic syntheses. With regard to equipment, the membranes open up new techniques, extending beyond conventional two- and multi-compartment cells, which have become known as solid polymer electrolysis (SPE) and oxygen consuming cathode (OCE). Applications of the membranes, which are resistent to oxidizing acids and alkalies, are considered in the cases of alkali chloride electrolysis, soda production, decomposition of water, electrolysis of hydrochloric acid, and electrochemical synthesis of propylene oxide. Concepts of the relationships governing OH^? ion migration through the membrane and the associated problems are essential if membrane cells are to be operated economically. Only in this way can the operating conditions be chosen optimally and the specific concentration-dependent properties of the membranes be fully exploited by chemical reaction engineering modifications, e.g. by a countercurrent cascade arrangement. Granted comparable economics the advantages of membrane equipment over conventional processes lie in a reduced environmental burden and possibly far lower energy consumption (which, however, may have to be bought at the price of additional investment). These advantages may be offset by the detrimental foreign ion content of the electrolyte, possible low current density, undesired by-product formation, back-diffusion processes, limited lifetime, combined with the high price of the membranes and the low maximum area of the individual cell; solution of these latter problems will further enhance performance.     

Electrochemical bromination and oxidation of alkyl aromatic compounds by two-phase electrolysis

A simple, regioselective, environmentally clean and economical method for the preparation of side chain/ ring brominated aromatic compounds is reported in 70–98% yield by an electrochemical method using two phase electrolysis technique. Electrochemical reactions were carried out using aqueous 25–50 wt% sodium bromide containing catalytic amount (5 wt%) of hydrobromic acid as an aqueous phase and chloroform containing alkyl aromatic compounds as an organic phase, at a temperature of 0–30 °C in an undivided cell. The same two-phase electrolytic system can be used for the oxidation of benzylic alcohols to the corresponding benzaldehydes in 80–94% yield without over oxidation to carboxylic acids. The advantage of this very mild procedure is a room temperature reaction used with an undivided cell. Excellent conversions are observed. After completion of alcohol oxidation the electrolyte can be reused for a number of times, demonstrating “spent reagent” free electro organic reaction as an attractive one. In the case of side chain/ring bromination of alkyl aromatic compounds, the electrolyte can be reused after making up the concentration of the electrolyte with 47 wt% HBr solution. In some cases homogeneous electrolysis is applied, where the two-phase electrolysis did not work. Styrene epoxidation and α-bromination of ketones underwent homogeneous electrolysis at room temperature without any catalyst. The reaction was performed in CH₃CN-water (3: 2) using equimolar amount of NaBr as an electrolyte to get 68% of styrene epoxide. Use of an ionic liquid 1-butyl 3-methyl imidazolium bromide (Bmim) Br, instead of NaBr improved the yield and current efficiency of styrene epoxide to 86%.     

生物电化学

生物电化学即运用电化学的技术、原理和理论来研究生物学事件。本文对生物电化学的研究范围及其在生物伽伐尼电池、生物燃料电池、传感器电极、膜电位等领域中的应用作了简单介绍。     

碱性体系中煤中有机硫的电化学脱除研究

以高硫煤为原料,用化学法将其无机硫脱除后,再以此作为电解煤样,在碱性条件下研究了煤中有机硫的电化学脱硫规律。讨论了电解电流、煤浆浓度、NaOH浓度等主要因素对煤中有机硫脱硫率的影响,并确定了适宜电解脱硫条件:NaOH质量浓度4.0mol/L,煤浆质量浓度0.04g/mL,反应温度70℃,电流强度1.0A,电解时间5h,获得了有机硫脱除率为32.50%的较好效果。     

Liquid–liquid electro-organo-synthetic processes in a carbon nanofibre membrane microreactor: Triple phase boundary effects in the absence of intentionally added electrolyte

An amphiphilic carbon nanofibre membrane electrode (ca. 50 nm fibre diameter, 50–100 μm membrane thickness) is employed as an active working electrode and separator between an aqueous electrolyte phase (with reference and counter electrode) and an immiscible organic acetonitrile phase (containing only the redox active material). Potential control is achieved with a reference and counter electrode located in the aqueous electrolyte phase, but the electrolysis is conducted in the organic acetonitrile phase in the absence of intentionally added supporting electrolyte. For the one-electron oxidation of n-butylferrocene coupled to perchlorate anion transfer from aqueous to organic phase effective electrolysis is demonstrated with an apparent mass transfer coefficient of m = 4 × 10⁻⁵ m s⁻¹ and electrolysis of typically 1 mg n-butylferrocene in a 100 μL volume. For the two-electron reduction of tetraethyl-ethylenetetracarboxylate the apparent mass transfer coefficient m = 4 × 10⁻⁶ m s⁻¹ is lower due to a less extended triple phase boundary reaction zone in the carbon nanofibre membrane. Nevertheless, effective electrolysis of up to 6 mg tetraethyl-ethylenetetracarboxylate in a 100 μL volume is demonstrated. Deuterated products are formed in the presence of D₂O electrolyte media. The triple phase boundary dominated mechanism and future microreactor design improvements are discussed.     

Recent Applications of Paired Electrolysis in Organic Synthesis

Recent years have witnessed a renaissance of organic electrochemistry since the cheap, safe, sustainable electron could be employed as a traceless redox agent to facilitate redox conversions. Additionally, divergent selectivity could be achieved by tuning the potential or current of the electrochemical reaction. Compared to electrooxidation or electroreduction reactions, paired electrolysis represents a more practical and energy-efficient strategy that delivers the products by making use of both anodic and cathodic reactions simultaneously. This mini-review summarized the breakthroughs and recent advances in this fascinating field and mainly is divided into three parts: parallel, sequential, and convergent paired electrolysis.     

电解法在环保领域中的应用

综合分析了近年来电解法在环保领域中的应用及研究进展情况.重点阐明电解法处理重金属废水、碱性废水、酸性废水、含氰废水、制药废水和有机废水,同时提出了电解法废水处理技术目前存在的问题及今后发展的方向.     

O_3协同内电解处理分散艳蓝E-4R废水的研究

基于印染废水具有成分复杂、色度高、难降解物质多等特点,采用臭氧协同内电解(IE/O3)对分散艳蓝E-4R进行处理。实验结果表明,在染液浓度为1 g/L加入铁屑量为300 g,通臭氧进气量为150 L/h,pH=11,反应温度为40℃,铁屑粒径为0.9~2 mm,铁炭比为1∶1时处理效果最佳,脱色率、CODC r去除率和TOC去除率分别为99.66%,75.94%和56.84%。臭氧协同内电解在最佳条件下处理染液的脱色率和CODC r去除率均明显高于二者单独作用,CODC r去除率分别比单独作用高59.03%和37.63%。另外,比较降解染液中的有机卤化物的含量,发现在协同作用下对该染料的降解更为彻底,矿化程度更高,有机氯化物去除率达到50.60%。