固体超强酸进展及其在酯化反应中的应用

较详细地介绍了各种固体超强酸的进展，尤其重点介绍了ＳＯ２－４／ＭｘＯｙ型固体超强酸的制备条件对超强酸性能的影响、性能改进的方法及其失活与再生。最后介绍了固体超强酸在酯化反应中的应用。     

稀土固体超强酸催化合成乙酸异戊酯的研究

制备出一系列稀土固体超强酸催化剂 ,用于催化以乙酸和异戊醇为原料合成乙酸异戊酯的反应。研究了稀土固体超强酸的催化性能 ,同时 ,考察了影响合成反应的因素。结果表明 ,稀土固体超强酸不仅具有一般超强酸的性能 ,而且催化活性更高 ,性能更稳定。     

固体超强酸进展及其在酯化反应中的应用

较详细地介绍了各种固体超强酸的进展，尤其重点介绍了ＳＯ＾２－４／ＭｘＯｒ型固体超强酸的制备条件对超强酸性能的影响，性能改进的方法及其失活与再生。最后介绍了固体超微酸在酯化反应中应用。     

复合固体超强酸催化酯化反应研究进展

相对于单组分固体超强酸而言,复合固体超强酸是一类性能更加优异的催化材料,具有更好的催化性能、选择性及重复使用性,不腐蚀设备,对环境污染小,是目前催化材料领域研究的热点。综述了复合固体超强酸作为酯化反应催化剂的应用情况。提出了复合固体超强酸的研究方向。     

固体超强酸SO_4~(2-)/M_xO_y催化剂的研究进展

主要介绍了固体超强酸催化剂的制备方法及对其改性的研究进展,综述了固体超强酸的应用,并对固体超强酸的开发应用前景进行了展望.     

杂多酸催化合成烷基葡萄糖多苷

报道了固体超强酸做催化剂合成烷基葡萄糖多苷的反应 ,并讨论了固体超强酸的最佳反应活性 ,葡萄糖转化率达 98.5%。     

超强酸及其应用

一、超强酸超强酸是指比100%硫酸酸性更强的酸,是一种连蜡烛都能溶解的强酸。超强酸对有机化合物具有非常强的作用能力。一些必须在高温下才能进行的饱和烃的反应,在超强酸的作用下,可在室温条件下进行,它甚至可以使对离子反应无甚活性的甲烷发生离子型反应。我们     

超强酸催化剂的研究进展

综述了超强酸催化剂的研究及应用进展状况，提出了某些超强酸的酸中心模型     

超强酸

<正>由于超强酸的发现,以往认为硫酸等是最强酸的传统观念已不再适用了。近十多年来,超强酸化学迅速发展,目前已合成了比100％的硫酸强10~(12)～10~(16)倍的超强酸。固体超强酸也纷纷涌现。由于超强酸具有特强的酸性和很高的催化活性,可以引发许多原来不能进行的反应,作为一类极有前途的催化剂而受到广泛的重视。此外在超强酸中能形成稳定的阳离子,有可能直接观察并研究它的结构和性质,从而开创了碳正离子化学的新领域。本文扼要叙述了超强酸的发现、酸度表示、分类、制备方法及催化反应。     

固体酸催化假紫罗兰酮合成紫罗兰酮研究进展

固体酸催化剂可成为制备紫罗兰酮的环境友好型催化剂,综述金属盐、阳离子交换树脂、固体超强酸、分子筛和杂多酸等固体酸在催化假紫罗兰酮环化反应中的应用,固体超强酸是目前的研究热点,存在易失活、不易保存和稳定性不足等问题。通过对催化剂载体改性、加入其他金属或氧化物形成多组元固体超强酸、引入稀土元素或特定的分子筛改性制备固体超强酸以及引入纳米级金属氧化物制备出纳米型固体超强酸等,这些均可为催化剂提供合适的比表面积、增加酸中心密度、增加酸种类型、增加稳定性和提高机械强度。     

固体酸催化合成乙酸环己酯评述

固体酸是有机合成中能够替代硫酸的良好催化剂。评述了磺酸、无机盐、固体超强酸、杂多酸和分子筛等固体酸催化合成乙酸环己酯的方法。认为甲烷磺酸盐、氨基磺酸、强酸性阳离子交换树脂、结晶硫酸氢钠、固体超强酸和杂多酸适合催化合成乙酸环己酯。     

Friedel-Crafts酰基化催化剂的研究进展

Friedel-Crafts酰基化反应在有机合成研究与现代工业生产中有着非常重要的作用,其催化剂主要有 Lewis酸、超强酸/盐、离子液体、沸石类以及负载型催化剂。本文分别介绍了上述五类催化剂在F-C酰基化反应中的发展沿革与目前应用情况,分析评价了各类催化剂在该反应中的优缺点,并重点综述了沸石类催化剂和负载型催化剂的研究现状。最后从绿色化学、可持续发展的角度出发,指出沸石类和负载型两类催化剂具有较好的综合催化性能和工业化应用前景,值得进一步研究。     

Friedel‐crafts alkylation of diphenyl oxide with 1‐decene over sulfated zirconia as catalyst

Friedel‐Crafts alkylation and acylation reactions, using highly polluting homogeneous Lewis and Bronsted acids, are ubiquitous in a variety of organic process industries. In many cases very high conversions and selectivities can be achieved with aluminum chloride as catalyst and nitrobenzene as a solvent. However, environmental concerns associated with aluminum chloride‐nitrobenzene or BF3‐HF or mineral acids catalysts have encouraged development of solid acids, which not only intensify the rates of reactions but also offer better product selectivity. Amongst these catalysts, sulfated zirconia has gained a considerable importance due to its super‐acidity under certain conditions. The alkylation of diphenyl oxide with 1‐decene was studied over sulfated zirconia catalyst and it leads to industrially important products. The surface reaction between chemisorbed 1‐decene diphenyl oxide from the liquid phase, in the absence of any mass transfer resistance, was found to be the rate determining step with Eley‐Rideal type of mechanism.     

Formation of organic acids from propane, isooctane and toluene/isooctane flames

Three fuels (propane, isooctane and toluene/isooctane) are used for the study of the formation of organic acids from their flames. Four organic acids have been found in the combustion products: formic, acetic, propionic and isovaleric acid. These acids are formed very quickly; their concentration then generally increases to reach a maximum value, and then decreases to zero. Toluene enhances the formation of organic acids comparing to propane and isooctane. The concentration of these acids depends strongly on the air/fuel equivalence ratio. Some correlations are found between the concentration of the acids and some alcohols or aldehydes. These results are in accordance with those presented in the case of internal combustion engines.     

石油羧酸盐表面活性剂溶液体系分析

本文对石油羧酸盐表面活性剂溶液体系进行了系统分析。发现溶液中不仅仅含有羧酸盐，还含有饱和烃、芳烃，酮、醇和极性物等化合物，用气相色谱法测定了各族组分的碳数范围，估算了羧酸的平均分子量M^-W＝251。由波谱分析证明，羧酸中除脂肪酸外，还含有带芳环、羟基、烯键等基团的有机酸存在。     

生物基有机酸提取分离技术研究进展

有机酸如乳酸、琥珀酸、柠檬酸、衣康酸、苹果酸等在工业上有重要应用,随着食品、医药、化学合成等工业的发展,有机酸需求骤增,发酵生产有机酸逐渐成为生物工程领域中一个重要而成熟的分支,但存在产物浓度低、成分复杂、后处理量大等问题. 有机酸亲水性好、不同有机酸物理化学性质相近等特点导致产物分离提纯困难,成为制约生物法生产有机酸的瓶颈. 分离发酵液中有机酸的方法主要有沉淀法、萃取法、吸附法、离子交换法、膜分离法、电渗析法和酯化法等. 通过各种分离方法的对比,发现单一的分离方法很难有效分离有机酸. 集成不同分离方法,可简化分离工艺,分离效果更好. 此外,采用新型分离耦合技术,可实现有机酸的连续或半连续生产,是未来发酵行业的一个重要发展方向.     

BINARY EXTRACTION OF PLATINUM METALS

ABSTRACT

The equations describing the regularities of interphase distribution of platinum metals as their chloro complex acids in systems containing binary extractants have been derived. The dependencies of distribution coefficients of platinum metals on the composition of both phases, and their aqueous acidity have been determined when both binary extraction and a combination of anion-exchange and binary extraction occurred. The interrelation of the binary extraction constant of chloro complex acids of platinum metals with the extraction constant of hydrochloric acid and the anion-exchange constant is described. We studied platinum metal extraction by salts of organic acids and organic bases and showed that in the systems involving binary extractants, such as salts of quaternary ammonium bases, the distribution of platinum metals proceeds via either anion-exchange or binary mechanisms depending on the composition of the system. With increasing pH, the distribution coefficients of platinum metals decrease according to the regularities of binary extraction due to forming thermodynamicaHy stable binary extractants, R4NA

When the anion-exchange extraction occurs, the distribution of complex acids of platinum metals in the systems containing binary extractants is affected by interactions of the extractants and the extracted compounds with the organic acids. Interactions between extractants in the chloride form and the molecules of organic acids have been shown to be largely responsible for the extraction characteristics. The binary extractant systems are preferred in the development of solvent extraction processes for the recovery and the stripping of platinum metals.     

Extraction of some mineral acids by high molecular weight quaternary ammonium chloride

The distribution equilibria of hydrochloric, nitric, perchloric, sulphuric and phosphoric acids between aqueous solutions and a solution of tricaprylmethyl-ammonium chloride in organic solvent have been investigated. The organic phases have been studied by infra-red and nuclear magnetic resonance spectroscopy. As a result, it is found that at low aqueous acidity the extraction of these acids is governed by the ion exchange reaction, forming the mono-quaternary ammonium salts of monobasic acids and the mono-, di- (and tri-) quaternary ammonium salts of di- (and tri-) basic acids, and at higher acidity by the formation of the adducts to quaternary ammonium salts with additional acids.     

液体酸耦合体系催化C4烷基化研究进展

综述了近十年来液体酸耦合体系催化C₄烃烷基化反应的最新进展,包括液体超强酸、有机酸-杂多酸、离子液体-酸耦合体系,对比了不同催化体系催化C₄烃烷基化反应过程中的烯烃转化率、三甲基戊烷的选择性和烷基化汽油的研究法辛烷值,总结了不同催化体系的优缺点。重点论述了离子液体-酸耦合体系催化剂中组成离子液体的阴阳离子以及耦合酸类型对C₄烃烷基化反应的影响：有机胺类离子液体较咪唑类有着更为优异的烷基化效果,阴离子和改性离子液体通过形成特定的结构来维持反应体系的酸强度、减少副反应,从而延长催化剂的使用寿命,耦合酸为反应提供酸性位点并与离子液体协同催化。离子液体-酸耦合催化体系具有酸耗低、稳定性好、不易失活且可循环使用等优点,是C₄烷基化催化剂未来的发展方向之一。