PVP-蒙脱土双负载Pd-Sn催化剂催化芳香卤化物水相脱卤

负载型双金属催化剂 ,由于双金属的协同作用 ,使催化活性明显提高 .因而负载型双金属催化剂用于催化有机反应 ,已成为人们研究的热点 .高聚物负载双金属催化剂催化有机卤化物脱卤已有报道[1～ 3] ,但脱卤反应大多在有机相中进行 ,若在水相中 ,催化剂则失去活性[2 ] ,且不易回收和重复使用 .然而有毒的卤化物常存在于化工、印染等工业排放的废水中 ,这些废水流入江、河、湖、海或渗漏在地下 ,造成对水体的严重污染 .为消除废水中有机卤化物对环境的污染 ,我们将 PVP(聚乙烯吡咯烷酮 )负载双金属后再负载到无机载体蒙脱土( Mont K1 0 )上 ,…     

双负载双金属催化剂催化芳香卤化物水相脱卤的研究

用PVP（聚乙烯吡咯烷酮）配合双金属Pd—Mn后,再负载于PEG400（平均分子量为400的聚乙二醇）官能化的高岭土上,制成双负载双金属催化剂PVP—PdCl2-MnCl2／GLM—PECA00,用于催化不溶于水的芳香卤化物水相脱卤,对芳香氯化物呈现出高的脱氯活性,重复使用六次转化率仍可达到62．14％,通过IR,TEM,XPS的表征对催化剂各组分在催化脱卤中的作用进行了探讨．     

官能化硅胶负载Pd—Cu催化剂的制备及催化芳香氯化物水相脱氯作用

将聚乙烯吡烷酮（PVP）与双金属Pd^2 、Cu^2 配位后,再负载于用平均分子量为600的聚乙二醇（PEG）官能化的硅胶上（SiO2-PEG600),制成一种新型双负载双金属催化剂PVP-PdCl2-CuCl2/SiO2-PEG600,将其用于催化难溶于水的芳香卤化物水相脱卤,在无需加入任何有机溶剂的情况下,对芳香氯化物呈现出高的脱氯活性和选择性,并具有良好的重复使用性能。通过IR、TEM、比表面积测定等手段,探讨了催化剂各组分在催化脱卤中的作用及可能的催化脱卤机理。     

PVP-PdCl2-SnCl4/MontK10-PEG400的制备及催化芳香卤化物水相脱卤研究

用PVP(聚乙烯吡咯烷酮)络合双金属Pd2 ,Sn4 后，再负载于PEG400(平均式量为400的聚乙二醇)官能化的蒙脱土上，制成双金属催化剂PVP-PdCl2-SnCl4/MontK10-PEG400，用于催化不溶于水的芳香卤化物水相脱卤，对芳香氯化物呈现出高的脱氯活性和选择性，并有良好的重复使用性，通过IR，TEM，XPS等手段测定对催化剂各组分在催化脱卤中的作用进行了探讨．     

PVP-PdCl2-CuCl2/SiO2-PEG600催化芳氯化物水相脱氯研究

PVP(聚乙烯吡咯烷酮)负载双金属催化剂催化芳香氯化物脱氯已有报道[1～3];利用双金属的协同作用,可以大大提高催化剂的脱氯活性和选择性[4]. 但是,这些研究多是在有机相中进行的,催化剂在水相中则会降低甚至失去活性,且难以回收和重复利用. 然而,难溶于水的有毒芳香氯化物,常存在于工业或生活排放的废水中. 由于治理环境的需要,研究芳香氯化物催化水相脱氯,则是极具挑战性的课题. 本文把起相转移作用的聚乙二醇(PEG)键合到硅胶上作为固相载体,制成双负载双金属水相脱氯催化剂PVP-PdCl2-CuCl2/SiO2-PEG600,成功地用于难溶于水的芳香氯化物的水相脱氯. 研究结果表明,这种催化剂对于芳香氯化物有良好的催化脱氯性能,使用中便于分离并能重复利用. 同时,用IR,TEM和XPS等手段对催化剂进行了表征,探讨了催化剂中各组分在催化脱氯中的作用.     

PVP负载Pd-Co催化剂催化六氯苯的加氢脱氯

研究了温和条件下钯催化剂催化六氯苯加氢脱氢反应． 结果表明, Ｐｄ Ｃｌ２ 催化活性不高,而 Ｐ Ｖ Ｐ 负载 Ｐｄ Ｃｌ２ 活性较高． Ｐ Ｖ Ｐ 负载 Ｐｄ Ｃｏ 催化剂具有双金属协同效应,提高了催化活性．５５ ℃下,该催化剂在 Ｃｏ／ Ｐｄ 摩尔比为０５ 时表现出最高的催化活性．     

蒙脱土负载钯催化的氢酯基化反应

蒙脱土负载钯催化的氢酯基化反应李文革李纪生１）吉改姣陈传峰（中国科学院化学研究所北京１０００８０）关键词氢酯基化烯烃钯蒙脱土非均相催化分类号Ｏ６４３．３２尽管均相催化反应显示出高催化活性和高选择性的优越性，但催化剂与产物的分离，以及催化剂的回收，特别...     

蒙脱土负载钯催化芳基溴化物脱溴性能研究

芳基溴化物催化脱溴,无论在有机合成,还是消除芳基溴化物对环境的污染方面均具有重要意义.催化脱卤已有许多研究报道[1].常用的负载催化剂为Pd/C[2],这种催化剂催化活性较高,但对不同卤素的选择性较差,贵金属钯损失较大.     

蒙脱土负载Pd/Cu双金属纳米微粒催化Sonogashira偶联反应

为了证实过渡金属催化碳碳键交叉偶联反应的双金属效应,首次研究蒙脱土负载纳米钯铜双金属微粒催化Sonogahira交叉偶联反应.结合蒙脱土重金属吸附特性与DMF溶剂热羰化还原,发展了一种新的双金属纳米微粒合成方法,制备了钯铜比例为1∶1的双金属纳米微粒.催化条件优化实验发现,乙二醇二甲醚/水(V∶V=1∶4)混合体系为最佳溶剂.碳酸钾与三苯基膦存在下,MMT@Pd/Cu高效催化芳基碘与系列端炔的交叉偶联反应,以较好产率分离得到15个炔烃衍生物.动力学研究表明,水对蒙脱土片层的溶胀作用与Pd/Cu双金属协同效应是该催化剂高活性的关键.     

官能化蒙脱土负载PVP-Pd-Sn催化芳香卤化物水相脱卤

有机卤化物长期以来一直在生产、科研中被广泛应用.这些物质排放进入水体后,造成对水体的污染,其中芳香卤化物是危害人类健康的有毒物质.为消除污染,研究芳香卤化物水相脱卤具有重要的意义.     

Dechlorination of Aromatic Chlorides in Aqueous System Catalyzed by Functionalized MontK10 Supported Palladium—tin

A novel bisupporter binetal catalyst PVP-PdCl2-SnCl4/MonK10-PEG400,using for dehalogenation of insoluable aromatic halides in aqueous system,has shown high dechlorination activity and selectivity,without any organic solvent or phase transfer catalyst.The conversion of aromatic chlorides can reach 100%.The catalyst is easy to prepare and has good reusability.     

Sensitive determination of polycyclic aromatic hydrocarbons in water samples by HPLC coupled with SPE based on graphene functionalized with triethoxysilane

The graphene functionalized with (3‐aminopropyl) triethoxysilane was synthesized by a simple hydrothermal reaction and applied as SPE sorbents to extract trace polycyclic aromatic hydrocarbons (PAHs) from environmental water samples. These sorbents possess high adsorption capacity and extraction efficiency due to strong adsorption ability of carbon materials and large specific surface area of nanoparticles, and only 10 mg of sorbents are required to extract PAHs from 100 mL water samples. Several condition parameters, such as eluent and its volume, adsorbent amount, sample volume, sample pH, and sample flow rate, were optimized to achieve good sensitivity and precision. Under the optimized extraction conditions, the method showed good linearity in the range of 1–100 μg/L, repeatability of the extraction (the RSDs were between 1.8 and 2.9%, n = 6), and satisfactory detection limits of 0.029–0.1 μg/L. The recoveries of PAHs spiked in environmental water samples ranged from 84.6 to 109.5%. All these results demonstrated that this new SPE technique was a viable alternative to conventional enrichment techniques for the extraction and analysis of PAHs in complex samples.     

A green and efficient oxidation of benzylic alcohols using H2O2 catalyzed by Montmorillonite-K10 supported MnCl2

<正>Primary and secondary benzylic alcohols were oxidized to the corresponding carbonyl compounds in good to high yields by environmentally friendly and green oxidant,H_2O_2 catalyzed by Montmorillonite-K10 supported manganese(Ⅱ) chloride.     

Nucleophilic substitution of ferrocenyl alcohols catalyzed by bismuth(III) in aqueous medium at room temperature

A nucleophilic substitution reaction of an α‐ferrocenyl alcohol with various amines, indoles and thiols was successfully developed by using a catalytic amount of Bi(NO₃)₃.5H₂O at room temperature without the aid of phase transfer catalyst. The reactions proceeded in aqueous media, leading to the formation of new C=C, C=N and C=S bonds bearing ferrocenyl substituent with high efficiency. Copyright © 2012 John Wiley & Sons, Ltd.     

A green and efficient deoximation using H202 catalyzed by montmorillonite-K10 supported COC12

Oximes were oxidized to the corresponding carbonyl compounds in good to high yields by environmentally friendly and green oxidant, H202 catalyzed by montmorillonite K-10 supported cobalt（Ⅱ） chloride.     

A green and efficient oxidation of benzylic alcohols using H2O2 catalyzed by montmorillonite K-10 supported CoCl2

Primary and secondary benzylic alcohols were oxidized to the corresponding carbonyl compounds in good to high yields by environmentally friendly and green oxidant, H2O2 catalyzed by montmorillonite K-10 supported cobalt（Ⅱ） chloride.     

Anionic synthesis of aromatic amide and carboxyl functionalized polymers. Chain-end functionalization of poly(styryl)lithium with N,N-diisopropyl-4-(1-phenylethenyl)benzamide

The novel syntheses of N,N-diisopropyl-4-benzoylbenzamide, N,N-diisopropyl-4-(1-hydroxy-1-phenylethyl)benzamide, and N,N-diisopropyl-4-(1-phenylethenyl)benzamide ( 1 ) are described. ω-Amidopolystyrene ( 2 ) was synthesized in quantitative yields by the reaction of poly(styryl)lithium with stoichiometric amounts of N,N-diisopropyl-4-(1-phenylethenyl)benzamide ( 1 ) in toluene/tetrahydrofuran (4 : 1 v/v) at −78°C. Deblocking of the amide protecting group by acid hydrolysis quantitatively provides the corresponding aromatic carboxyl chain-end functionalized polystyrene ( 3 ). The functionalization agent and functionalized polymers were characterized by HPLC, thin-layer chromatography, size exclusion chromatography, vapor phase osmometry, spectroscopy (¹H-NMR, ¹³C-NMR, and FTIR), potentiometry, and elemental analysis. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1233–1241, 1998     

硫酸铯/聚乙二醇双水相体系在298.15K的相平衡

水溶性高聚物的双水相体系可用于纯化一些无机盐,获得高纯晶体。由于高聚物的存在会减小盐在溶液中的溶解度,从而可能析出晶体。本文采用自制的相平衡装置,测定了硫酸铯／聚乙二醇(PEG1000,4000,10000)双水相体系在298．15K时的等温平衡溶解度。