Electrochemical Synthesis of p-(β-Hydroxyethyl Sulfone) Aniline

本文研究了以对-硝基苯基-β-羟乙基砜为原料在铅板电极上电化学还原制备对-（β-羟乙基砜）苯胺的反应,探究电流密度、通电量、温度和硫酸浓度对电流效率和产率的影响。在最优条件下（电流密度300 A·m-2,理论通电量6.0 F·mol-1,温度70℃,硫酸浓度1.5 mol·L-1）,该反应的电流效率达到92.7%,产率达到93.0%。在该最优条件的基础上向电解液中加入质量分数2.0%的硫酸钛可将产率提升至97.8%,硫酸钛的引入间接缓解了反应后期原料扩散速率慢的问题。Para-ester is the most important intermediate for the preparation of ethylene sulfone type reactive dyes, which is usually used in the dyeing of cellulose fibers and synthetic fibers. P-(β-hydroxyethyl sulfone) aniline is an important intermediate for the synthesis of para-ester. In this paper, p-(β-hydroxyethyl sulfone) aniline was prepared by electrochemical method, having the advantages of simple process, mild reaction condition, less environmental pollution, easy reaction control and so on. It has strong development potential and industrial application prospect. The electrochemical reduction of p-nitrophenyl-β-hydroxyethyl sulfone on a lead plate electrode to prepare p-(β-hydroxyethyl sulfone) aniline was investigated, and the reaction was carried out in a two-cell cationic diaphragm electrolytic cell. The electrolysis parameters, such as current density, electricity quantity, temperature and concentration of sulfuric acid, were firstly optimized to achieve a desirable current efficiency and excellent yield of p-(β-Hydroxyethyl Sulfone) Aniline. Under the optimal conditions (current density: 300 A·m-2, electricity quantity: 6.0 F·mol-1, temperature: 70℃, sulfuric acid concentration: 1.5 mol·L-1), the current efficiency and yield of the target reaction reached 92.7% and 93.0%, respectively. Moreover, the introduction of 2.0% mass fraction of titanium sulfate additive to the electrolyte could indirectly alleviate the problem of slow diffusion rate of raw material in the late stage of electrolysis, which, in turn, could further increase the yield to 97.8%. At the later stage of reaction, as the concentration of raw materials decreased, the difference between the concentration in the body solution and the electrode surface became smaller, and the diffusion rate of raw materials from the solution to the electrode surface became slower, resulting in a slow reduction reaction rate. After adding titanium sulfate, Ti4+ was mainly diffused to the electrode surface in the late reaction solution, and Ti3+ with strong reducing property was reduced on the electrode surface. The p-nitrophenyl-β-hydroxyethyl sulfone and hydroxylamine intermediate of low concentrations were reduced to p-(β-hydroxyethyl sulfone) aniline, thus, improved the yield and current efficiency. The reduction of p-nitrophenyl-β-hydroxyethyl sulfone to p-(β-hydroxyethyl sulfone) aniline was determined by cyclic voltammetry and high resolution liquid-mass spectrometry. First, p-nitrophenyl-β-hydroxyethyl sulfone was reduced to hydroxylamine intermediate by 4 electrons, and then hydroxylamine intermediate was further reduced to p-(β-hydroxyethyl sulfone) aniline by 2 electrons, and the whole reaction process was a 6-electron reaction. This method provides a new process route for the syntheses of p-(β-hydroxyethyl sulfone) aniline and para-ester, which is beneficial to solve for the problems of environmental pollution and high production cost in the current production process.国家重点研发计划项目(2017YFB0307502)通讯作者:钮东方,张新胜E-mail:[email protected];[email protected]:Dong-FangNiu,Xin-ShengZhangE-mail:[email protected];[email protected]华东理工大学化学工程联合国家重点实验室,上海 200237State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, Chin

Effect of Alkyl Chain Length of Symmetrical Quaternary Ammonium Hydroxide on Oxalic Acid Electroreduction Reaction

研究了四种不同烷基链长度的对称季铵碱对草酸电还原制备乙醛酸反应的影响。线性扫描测试考察了添加剂对铅电极上阴极反应的影响,结果表明对称季铵碱在电极表面的吸附对析氢反应的抑制程度大于其对草酸电还原反应的抑制程度,且随着对称季铵碱中烷基链长度的增加,添加剂抑制析氢反应效果更明显。计时安培法的结果证明添加剂可影响草酸向电极表面的扩散,随着对称季铵碱中烷基链长度的增加,草酸的扩散系数呈现出先增加后减小的趋势。恒流电解实验结果表明,添加剂能有效提高草酸电还原反应的电流效率,且提高效果随对称季铵碱所含烷基链长度的增加而增强。因此,添加剂的吸附对阴极表面析氢反应的抑制作用是草酸电还原反应电流效率提高的主要原因。本研究表明,四丁基氢氧化铵为添加剂时,草酸还原为乙醛酸的电流效率最高。Glyoxylic acid with the dual characteristics of acid and aldehyde is an important chemical raw material and organic synthesis intermediate, which is extensively used in the perfumery, pharmaceutical and fine chemical industries. A family of symmetric quaternary ammonium hydroxides (QAHs) with different alkyl chain lengths was used as the additives in generating glyoxylic acid from oxalic acid electroreduction reaction (OAER). The effects of alkyl chain length on OAER and the corresponding side reaction, i.e., hydrogen evolution reaction (HER), were investigated. Linear sweep voltammetric (LSV) results showed that the adsorption of the additives suppressed more on the HER than that on OAER, resulted in improving the current efficiency of OAER. As the alkyl chain length of QAH increased, the suppression effect on HER was more obvious. The effect of additives on oxalic acid diffusion was studied by chronoamperometry (CA). With the increase in the alkyl chain length of the QAH additives, the diffusion coefficient of oxalic acid increased first and then decreased. The constant-current electrolysis results showed that the additives could effectively improve the current efficiency of the OAER, which was highly related to the alkyl chain length of QAHs. The LSV, CA and electrolysis results indicate that the suppression effect of QAHs adsorption on HER is the main reason for the improvement of current efficiency. In this study, tetrabutylammonium hydroxide (TBAH) is the best additive to increase the current efficiency of generating glyoxylic acid from oxalic acid.通讯作者:胡硕真E-mail:[email protected]:Shuo-ZhenHuE-mail:[email protected]华东理工大学化学工程联合国家重点实验室,上海 200237State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, P.R. Chin

Bipolar-Membrane Electrodialysis Method to Treat Industrial High Saline Perfume Wastewater

采用双极膜电渗析法处理某企业的工业高盐香料废水，旨在将无机盐氯化钠从香料废水中脱除并转化为附加值更高、较高浓度的盐酸和氢氧化钠. 当一次性处理3 L废水时，保证了足够的处理时间，生成盐酸和氢氧化钠的浓度分别能达到1.93 mol·L-1和1.70 mol·L-1，脱盐率为99.4%，生成盐酸和氢氧化钠的电流效率分别为30.7%和36.0%，电耗为2.58 kW·h·kg-1. 分别通过向盐室中补加废水原料和氯化钠固体的方式，均可抑制盐室中氯化钠浓度的减小，将生成的氢氧化钠浓度显著地提高，且后者提高的程度更为明显. 为提高酸、碱产品的纯度，分别考察了阳离子交换膜和阴离子交换膜对Cl-和Na+的阻隔效果，阳离子交换膜对Cl-的阻隔效果有着JAM-II>N2030>TRJCM的顺序，阴离子交换膜JAM-II对Na+的阻隔效果高于TRJAM. JCM-II相比于N2030膜有着更低的膜电阻. 综合考虑使用JAM-II/BPM-I/JCM-II组合时效果最好，电耗最低.Large amount of organic saline wastewater is generated from various chemical industries. The contents of organic saline wastewater are more and more complicated as they are created from different types of industries. Directly discharging the organic saline wastewater without pre-treatment can generate severe environmental problem and waste useful resources. It is necessary to use an economical method to treat the organic saline wastewater and recover the salt into useful materials to achieve resource reuse. Bipolar-membrane electrodialysis (BMED) is one of the methods that can remove salt from the wastewater and convert it into certain acid and base with higher value than salt. After BMED process, the organicsleft in the treated wastewater can be further removed by normal methods. This research focuses on treating an industrial saline perfume wastewater, which contains high contents of NaCl and organic compounds, with BMED method. The purpose is to reduce the NaCl concentration and convert it into high valued acid and base with high concentrations. When 3 liters of wastewater were treated, the processing time is guaranteed. The concentrations of recovered acid and base were 1.93 mol·L-1 and 1.70 mol·L-1, respectively. The desalination rate reached 99.4%, and current efficient and electricity consumption were 30.7% and 2.58 kW·h·kg-1, respectively. By adding waste water raw material and NaCl solid in the salt compartment, the reduction of NaCl concentration in salt compartment could be inhibited, and the concentration of NaOH was increased significantly, and the degree of the latter became more obvious. For cathodic exchange membranes, their ability to prevent Cl- penetration decreased as following order: JCM-II＞N2030＞TRJCM. For anodic exchange membranes, JAM-II had better Na+ penetration preventing ability than TRJAM. JCM-II had lower membrane resistance, so that it consumed less electrical energy than N2030. Overall, a combination of JAM-II/BPM-I/JAM-II membranes showed the best performance and least electricity consumption.国家重点研发计划项目（No.2017YFB0307502）资助作者联系地址：华东理工大学化学工程联合国家重点实验室， 上海 200237Author's Address: State Key Laboratory of Chemical Engineering，East China University of Science and Technology，Shanghai 200237，China通讯作者E-mail：[email protected]

Recent Progress on Enhancing Effect of Nanosized Metals for Electrochemical CO2 Reduction

将二氧化碳通过电化学方法转化为化工原料再利用,不仅可以有效缓减温室效应,而且可以实现自然界的碳循环,对绿色化学与可持续发展意义重大. 本文简要地介绍了二氧化碳电还原的优势及其基本反应原理并综述了近年来基于纳米金属催化剂的一系列活性增强策略的研究进展. 重点探究了合金效应、界面工程、协同效应、缺陷工程以及载体效应等对纳米金属电催化还原二氧化碳性能的影响及相关反应机理. 基于以上策略,提出未来开发面向工业化应用的二氧化碳电还原催化剂面临的挑战与前景.The electrochemical conversion of CO2 to chemical raw material for further utilization shows promising future to alleviate global warming and realize carbon cycle in nature, which is of great significance to the green chemistry and sustainable development. This review briefly introduces the advantages of CO2 electrochemical reduction (CO2ER) and its basic reaction principles, and summarizes the recent progress in a series of activity enhancement strategies based on nanosized metal catalysts. The influences of alloy effect, interface engineering, synergistic effect, surface defect engineering and support effect on the catalytic performance of nanosized metals for CO2ER and the related reaction mechanisms are mainly reviewed. Based on the above strategy, the challenges and prospects for the future development of CO2ER catalysts for industrial applications are proposed.国家自然科学基金项目资助(21972042)通讯作者:钮东方,张新胜E-mail:[email protected];[email protected]:NIUDong-fang,ZHANGXin-shengE-mail:[email protected];[email protected]华东理工大学化工学院,化学工程联合国家重点实验室,上海 200237State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, Chin

Electrochemical Deposition of Cr from Cr(III)-Based [BMIM]HSO4 and NaOAc Electrolyte

本文研究了Cr3+在1-丁基-3-甲基咪唑硫酸氢盐（[BMIM]HSO4）电解液中的电沉积反应以及添加剂NaOAc对电镀铬的影响. 含Cr3+电解液的循环伏安结果表明，Cr(III)还原为Cr(II)的峰电位是-1.5 V (vs. Pt)， 峰电位和峰电流均满足Rendle-Sevcik扩散方程，由该方程计算得到Cr3+的扩散系数为1.6 × 10-8 cm2·s-1. 铬镀层的X射线衍射和扫描电子显微镜表征结果表明镀层由纳米球状的单质铬颗粒聚集而成，其平均粒径为0.87 μm. 在电解液中添加NaOAc后，Cr3+的还原峰电位正移了约0.25 V. 同时EDS结果表明，在NaOAc的作用下镀层中Cr/O摩尔比由4.48增加至6.28，这说明OAc-有利于单质铬的电沉积. 当电解液中NaOAc-[BMIM]HSO4-CrCl3-H2O的摩尔比为0.075:1:0.5:6时，所得的镀层最厚(63 μm)与电流效率最高(33.5%).Using trivalent chromium ions (Cr(III)) as the chromium source for chromium electrodeposition has attracted much attention since it can reduce the toxicity of the whole process. Even though the chromium deposition in Cr(III)-based ionic liquid bath can avoid the most hydrogen evolution problem, CrCl3·6H2O is widely used as the Cr(III) precursor, which still contains water and has the stable octahedral structure. As a result, it is difficult to deposit Cr and there is still hydrogen evolution reaction (HER). Moreover, the hydroxyl ions (OH-) produced during HER react with Cr3+ to form Cr(OH)3, which will affect the performance and property of the Cr layer. To avoid the formation of Cr(OH)3, 1-butyl-3-methylimidazolium hydro sulfate ([BMIM]HSO4) aqueous solution was used as the electrolyte in this work. To enhance the depositing ability and to lower the reduction onset potential of Cr(III), NaOAc was used as the additive. Electrochemical measurements such as cyclic voltammetry (CV) and linear sweep voltammetry (LSV) were made to test the electrochemical performance in different electrolytes. Chromium layers were electrodeposited on copper plates at a constant potential of -3.0 V (vs. Pt). The Cr thickness and current efficiency were calculated based on the gravimetric method. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX) techniques were used to study the surface morphology, crystalline structure and elemental composition of the deposited Cr layer, respectively. The cyclic voltammetric results showed that the reduction of Cr(III) to Cr(0) is a two-step process. First, Cr(III) reduced to Cr(II) at -1.50 V (vs. Pt). Then, Cr(II) further reduced to Cr(0) at -2.10 V (vs. Pt). Both of the peak current and peak potential followed the Rendle-Sevcik equation, by which the diffusion coefficient of Cr3+ at 40 ℃ was calculated to be 1.6 ×10-8 cm2·s-1. The XRD and SEM characterizations indicated that the Cr coating layers were composed of Cr nanoparticles with an average particle size of 0.87μm. The NaOAc effect on the electrodeposition of Cr was also studied. After adding NaOAc, the reduction peak potential of Cr(III)shifted to positive direction, indicating less energy required to reduce Cr3+. Additionally, the molar ratio of Cr:O in the coating layer increased from 4.48 to 6.28, indicating that OAc- was helpful for the electrodeposition of Cr metal. This was because the addition of OAc- could break the stable octahedral structure of CrCl3·6H2O. Overall, the best coating thickness (63 μm) and highest current efficiency (33.5%) were obtained when the molar ratio of NaOAc-[BMIM]HSO4-CrCl3-H2O electrolyte was 0.075:1:0.5:6. Based on this study, it can be concluded that [BMIM]HSO4-NaOAc aqueous electrolyte might be benefited to electrodeposit pure Cr, instead of Cr(OH)3, with relatively high current efficiency and low reduction onset potential.无作者联系地址：1. 华东理工大学化学工程国家重点实验室，上海 200237；2. 石油化工新材料协同创新中心，安徽 安庆 246011Author's Address: 1. State Key Laboratory of Chemical Engineering，East China University of Science and Technology，Shanghai 200237，China; 2. Collaborative Innovation Center for Petrochemical New Materials，Anqing 246011，Anhui，China通讯作者E-mail：[email protected]