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1.
BF_3/离子交换树脂固体酸催化剂的研究温陵生,马淑杰,张强,吕慧娟,徐征(吉林大学化学系,长春130023)关键词三氟化硼,聚苯乙烯磺酸树脂,全氟磷酸树脂,超强酸催化剂用于催化剂的离子交换树脂有大孔聚苯乙烯磺酸树脂PSSA和全氟磺酸树脂PFIEP(?..  相似文献   

2.
高分子分散钯催化剂催化对硝基苯酚加氢反应的研究   总被引:1,自引:0,他引:1  
制备了多种商品化的离子交换树脂和螯合树脂分散钯催化剂,考察了它们对对硝基苯酚加氢反应的催化活性。结果表明这些催化剂对对硝基苯酚的加氢反应有较高的活性,其中阴离子交换树脂和H型阳离子交换树脂分散钯催化剂活性最高。催化剂加氢活性与反应进程有关。  相似文献   

3.
在微波加热条件下,以732型阳离子交换树脂和ZnCl2改性离子交换树脂为催化剂,添加乙醇为溶剂,对生物油进行催化酯化改质.比较研究了两种催化剂随催化剂用量、反应时间及反应温度改变对生物油改质效果的影响,同时考察了微波加热与传统水浴加热条件下催化剂的活性.结果表明,酯化过程中ZnC12改性离子交换树脂比732型树脂活性有...  相似文献   

4.
用XPS分析由离子交换法制备的Ru-Cu双金属非均相催化剂,考察双金属交换顺序对催化剂性能的影响。结果表明,交换顺序对催化剂性能影响较大,先交换铜离子后交换钌离子有助于提高催化剂的活性。低价态金属元素是催化剂在反应状态下的活性组分。此外,离子交换液的pH值对催化剂性能的影响也较大,pH值偏碱性时有助于催化剂活性的提高。  相似文献   

5.
球形炭化树脂作为催化剂载体具有许多独特的优点,为炭素材料催化剂开拓了新的前景。在诸多炭化树脂催化剂的制备方法中,离子交换-炭化法具有许多优点,是重要的制备方法之一。本文从D152大孔弱酸阳离子交换树脂为前驱载体,用不同的预处理方法先制成钙型D152酸阳离子交换树脂为前驱载体,用不同的预处理方法先制成钙型D152树脂,然后同Ni的NH3-NH^+4水溶液、乙醇水溶液进行离子交换,再经炭化后制成了高分  相似文献   

6.
离子交换树脂固载SnCl4:合成,表征和酯化反应   总被引:2,自引:0,他引:2  
刘福安  田明原 《分子催化》1993,7(5):384-387
均相催化剂的固载化,由于具有独特属性,近年来发展很快.我们在用高分于材料固载路易斯酸的研究中,发现固载在离子交换树脂的路易斯酸催化性能非常稳定.本文将空气中强烈水解,且腐蚀性很强的四氯化锡与大孔苯乙烯系阳离子交换树脂反应,首次合成了离了交换树脂四氯化锡复合物(以下简写成压IER·SnCl_4),并对IER·SnCl_4的IR、UV光谱性质及在酯化反应中的催化性能进行了研究.结果表明IER·SnCl_4不仅活性高,而且在重复使用性能上表现了突出特点,显示了良好的应用前景.  相似文献   

7.
以732#强酸性阳离子交换树脂为载体,采用离子交换法合成了Ce4+改性离子交换树脂催化剂,考察了Ce4+浓度、吸附温度和pH值等因素对树脂改性的影响,并测试了催化剂的重复使用性能。结果表明,当Ce4+浓度为0.1mol/L左右,常温25℃、pH值接近中性时,Ce4+改性阳离子交换树脂的催化活性最佳,且重复使用6次仍保持较高的催化活性。试验利用红外光谱(FT-IR)、热重分析(TG)和能谱仪(EDS)等对改性树脂的结构进行分析表征,结果表明,改性后的树脂中氢元素大部分被Ce4+离子所替代,其酸性和稳定性均有所提高。将Ce4+改性732#阳离子交换树脂作为催化剂应用于生物柴油环氧化反应中,产物环氧值较高。  相似文献   

8.
全氟离子交换树酯[Perfluoririnted ion-exchange resin(PFIER)]由于其化学稳定性极好,因此用它作为高分子载体具有独特的优越性。全氟磺酸树脂作为强酸性催化剂,在有机合成中的应用已有广泛的研究。近年来,用高分子载体催化剂代替传统的小分子催化剂进行反应,由于后处理和催化剂回收方便而受到重视。但是,用含金属或金属阳离子的离子交换树脂作为金属催化剂参与的反应却研究得很少。  相似文献   

9.
离子交换树脂催化合成糠醛缩乙二醇的研究   总被引:2,自引:0,他引:2  
本文研究了在离子交换树脂存在下,由糠醛和乙二醇反应制备糠醛缩乙二醇的工艺条件。结果表明,用南开牌D61、D72离子交换树脂作催化剂,在回流温度下,用甲苯或环已烷作带水剂,反应可在1.5~3小时之内完成,产率可达93%左右。  相似文献   

10.
强酸离子交换树脂催化剂在有机合成中的应用   总被引:4,自引:0,他引:4  
本文综述了近几年来强酸离子交换树脂催化剂在水合、醚化和醚键裂解、脱水、缩醛化、酯化、水解、烷基化反应等方面的应用。  相似文献   

11.
氯甲基化苯乙烯-二乙烯苯共聚物在傅氏催化剂存在下与取代酚(芳香胺)反应可以得到一些含取代酚基的离子交换树脂。它们的物理化学性质和红外光谱分析证实了该类树脂的结构。溶剂的性质、催化剂的种类、用量、反应温度、时间、取代酚(芳香胺)的取代基位置、聚合物的含氯量和孔结构都对反应和副反应有明显的影响。这类离子交换树脂在重金属分离、脱色,特别在维生素和抗菌素的选择吸附等方面,都有十分重要的意义。  相似文献   

12.
Suzuki reactions catalysed by a palladium(II) complex of a functionalized bis(imidazolium) ligand, PdII(BIM), immobilized on Dowex 50 WX8 and Amberlite IR‐120 ion‐exchange resins as heterogeneous, recyclable and active catalysts are reported. The catalysts, PdII(BIM)@Amberlite IR‐120 and PdII(BIM)@Dowex 50 WX8, were characterized using Fourier transform infrared and diffuse‐reflectance UV–visible spectroscopies and scanning electron microscopy. These heterogeneous catalysts are oxygen‐insensitive and air‐ and moisture‐stable in C? C coupling reactions, and are reusable several times without significant loss of their catalytic activity. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

13.
The preparation of a variety of catalysts obtained by ion exchange of the complex [(dppb)Pt(μ−OH)]22+ with sulfonated styrene–divinylbenzene copolymers is reported. Copolymers used are commercial ion exchange resins containing either 4% or 20% DVB and they were loaded with either Li+ or NBu4+ prior to exchange with the Pt complex. Metal loading in the heterogenized catalysts is in the range 2–8% by weight. Their catalytic properties in the Baeyer–Villiger oxidation of methylcyclohexanone with hydrogen peroxide appear to be best in terms of activity and productivity either in neat ketone or in EtOH as the solvent. The use of commercial resins with high exchange capacity prevents the use of DCE as the solvent, i.e., the optimum conditions for the homogeneous system, thereby leading to activities and productivities that are generally lower than their homogeneous counterpart. A discussion on the influence of the philicity properties of the support with respect to the performance of the catalyst is reported.  相似文献   

14.
钯-高分子载体催化剂对糠醛加氢液相反应的研究   总被引:7,自引:0,他引:7  
以弱碱性苯乙烯系阴离子交换树脂[D392,-NH2,D382,-NHCH3,D301R,-NH(CH3)2],强碱性苯乙烯系阴离子交换树脂[201×7DVB,-NH+(CH3)3]和弱碱性环氧系阴离子交换树脂(701,-NH2)为载体制备了3种钯-高分子载体催化剂.考察了反应条件、高分子载体的种类、钯含量和催化剂用量对糠醛催化加氢生成四氢糠醇反应及催化性能的影响.在体积分数为50%的乙醇-水溶液和水中对糠醛常压液相加氢反应,钯-高分子载体(阴离子交换树脂D392,-NH2,D382,-NHCH3)催化剂均可使糠醛的加氢反应转化率达100%,生成四氢糠醇的选择性达98%以上,而用金属钯为催化剂的转化率达70%以上,选择性达97%以上.同时用XPS分析了高分子载体催化剂的结构与催化加氢反应性能的关系.  相似文献   

15.
Glycerol is a colorless, odorless, and non-toxic compound and has application in food, paint, and pharmaceutical industries. At an industrial scale, glycerol (GL) commonly forms as a by-product of soap and biodiesel producing industries. To utilize the excess GL of biodiesel industry, former has been employed as a building block to manufacture value added products such as acetins by fine chemical manufacturers. Acetins, including monoacertin (MA), diacetin (DA) and triacetin (TA), has diverse application such as in cosmetics, fuel additives, pharmaceuticals, leather, and food processing. Specifically, TA is employed as an additive to improve the anti-knocking property of gasoline and viscosity and cold flow properties of biofuel. The acetins are frequently produced at an industrial scale via a homogeneous Brønsted acid catalysed process employing acetic acid or acetic anhydride as an acetylating agent. Homogeneous acid catalysts are corrosive, non-reusable, difficult to separate from the reaction mixture, and sensitive to water, which is formed as a by-product during the glycerol acetylation. To address the issues, Brønsted or Lewis acidic group have been immobilized over various matrices (e.g., mixed metal oxides, mesoporous silica, ion exchange resins, carbon, zeolites, and magnetic nanoparticles) to prepare the heterogeneous acidic catalysts for the glycerol acetylation. Both the sites assisted the carbocation mediated esterification of glycerol with acetic acid or acetic anhydride. The ease of catalyst separation from the reaction mixture and reusability are the major advantages of their usage. However, lower conversion levels with low product selectivity, catalysts deactivation, and partial dissolution in the reaction mixture are the concerns related to the catalysts. To address these issues, novel catalyst preparation techniques to incorporate the variety of active sites over the matrix surface have been employed in the literature, which will be highlighted in detail in the present review article.  相似文献   

16.
The tetrakis(4‐N‐methylpyridinium)porphyrinatopalladium(II) iodide, [Pd(TMPyP)]I4, supported on Dowex 50WX8 and Amberlite IR‐120 ion‐exchange resins, was used as heterogeneous, recyclable and active catalyst for the Suzuki–Miyaura and Heck cross‐coupling reactions. These catalysts were applied to coupling of various aryl halides with phenylboronic acid and styrene in Suzuki and Heck reactions, respectively, and the corresponding products were obtained in excellent yields and short reaction times. The catalysts could be recovered easily by simple filtration and reused several times without significant loss of their catalytic activity. The catalysts were characterized by diffuse‐reflectance UV–visible spectroscopy and scanning electron microscopy, and their stability was confirmed by TGA. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

17.
具有精细结构的吸附与离子交换树脂   总被引:3,自引:0,他引:3  
本文论述了某些具有精细化学,物理结构的离子交换树脂和吸附树脂的特性与应用。  相似文献   

18.
Skeletal isomerization of 1-pentene   总被引:1,自引:0,他引:1  
Series of ZSM-5 and Y zeolite catalysts have been prepared. Zeolites were submitted to ion exchange, drying, formation with 50 wt.% of aluminium hydroxide as a binder and then to final thermal treatment. Determination of catalysts activity in 1-pentene isomerization reaction was carried out in the temperature range of 175–325°C. The highest activity in isomerization reaction was attained in the presence of ZSM-5 zeolite catalysts with strong and medium strength acidity.  相似文献   

19.
离子交换树脂催化对羟基苯甲酸酯化反应的研究*   总被引:16,自引:0,他引:16  
本文研究了一种固体酸催化剂一阳离子交换树脂催化剂,用于对羟基苯甲酸的酯化反应。通过对不同树脂进行筛选,发现JK008的催化活性比较高。本文还进一步考察了JK008催化剂的使用寿命,研究了合成对羟基苯甲酸乙酯的最佳反应条件。  相似文献   

20.
Crown ethers bound to microporous polystyrene resins by oxyethylene spacers were prepared by the reaction of monoazacrown ethers with 2-tosyloxyethoxymethylated or 2-(2-tosyloxyethoxy)ethoxymethylated polystyrene resins crosslinked with 2 mol % of divinylbenzene. The activity of the immobilized lariat crowns for halogen exchange reactions under triphase conditions has been studied as a function of catalyst structure, loading, substrate structure, reagent structure, and solvent. The lariat catalysts with extra oxygen donors in the spacer chain exhibited higher activity than the corresponding immobilized catalysts without the donors in the spacer. The increased activity of the catalyst containing 15-crown-5 unit and two extra donors for the reaction of 1-bromooctane with KI was concluded to result from the enhanced complexation with the K+ ion, induced by the cooperative coordination of the crown unit donors and the donors in the spacer chain. The recovered catalysts could be re-used without decrease in activity.  相似文献   

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