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1.
杂多酸和离子液体催化环己烯的清洁氧化反应研究   总被引:1,自引:2,他引:1  
路瑞玲  李臻  陈静  郎贤军 《分子催化》2007,21(3):268-271
以30%过氧化氢为氧化剂,考察了以杂多酸为催化剂氧化环己烯过程中离子液体的作用,讨论了离子液体种类和用量对反应的影响. 结果表明,离子液体的加入顺序不同,其在催化过程中所起的作用不同. 在反应条件为n(环己烯):n(过氧化氢):n(磷钨酸):n([(CH2)4SO3H-Py][HSO4])=1:4.4:0.28:0.56,在回流温度下反应8 h时,己二酸收率可达到84.9%.该催化剂体系可循环使用.  相似文献   

2.
以咔唑为原料,碳酸二乙酯为烷基化试剂,碳酸铯和三乙基苄基氯化铵为共催化剂,经烷基化反应绿色合成了N-乙基咔唑,其结构经1H NMR和HR-ESI-MS确证。在最佳反应条件[咔唑200 mmol,碳酸二乙酯1.2 eq.,碳酸铯(0.05 eq.)和三乙基苄基氯化铵(0.05 eq.)为催化体系,于180℃反应3 h]下,产率99%。  相似文献   

3.
合成了一种吡啶甲醛类Schiff碱铁配合物[Fe(PA2OPd)C12]Cl,并考察了配合物对环己烯绿色环氧化反应的催化活性及反应条件,结果表明:吡啶甲醛类Schiff碱铁配合物对环己烯的环氧化反应有比较高的催化活性及选择性.以过氧化氢为氧源、[Fe(PA2OPd)C12]Cl为催化剂、在pH=5.0左右的乙酸乙酯溶液中25℃反应6.0 h,环己烯转化率可达90.5%,环氧环己烷选择性可达97.2%.  相似文献   

4.
在以改性阳离子交换树脂为催化剂、H2O2为氧化剂的催化氧化体系中,主要研究和考察了环己烯直接氧化制备1,2-环己二醇的反应,并优化得到了最佳合成工艺,在无溶剂,H2O2与环己烯的摩尔比为1.0:1.0、反应温度为70℃、反应时间为6.5h、催化剂用量为环己烯摩尔量10%的反应条件下,环己烯的转化率大于99.0%,产品1,2-环己二醇的选择性大于98.0%。阳离子交换树脂催化剂重复使用12次未见其活性和选择性明显下降。在此反应条件下,直链状的1-己烯也可高效和高选择性地转化为1,2-己二醇。  相似文献   

5.
Ti4+修饰阳离子交换树脂催化制备环已烯   总被引:5,自引:0,他引:5  
在Ti^4 修饰阳离子交换树脂催化剂上进行了环己醇脱水制备环己烯的反应,考察了催化剂吸附毗啶的FT-IR,证实了该催化剂表面具有Bronsted酸和Lewis酸性住是催化环己烯脱水反应的物质基础,实验结果表明:修饰树脂具有较高的热稳定性,Ti^4 交换容量对阳离子交换树脂的催化活性存在着明显的影响,催化剂对环己醇脱水制环己烯反应的活性高,并得到该反应的优化条件如下:环己醇40g,催化剂5g,反应温度175℃,反应时问60min,在此条件下,环己烯的产率达89%。  相似文献   

6.
采用农药厂副产物三乙基-3-苯氧基苄基氯化铵与4-氯苯基环丙基酮肟在碱性的条件下反应合成4-氯苯基环丙基酮厉-O-(3-苯氧基苄基)醚,产率80%。  相似文献   

7.
俞明兴 《应用化学》1994,11(3):75-77
采用农药厂副产物三乙基-3-苯氧基苄基氧化铵与4-氯苯基环丙基酮肟在碱性的条件下反应合成4-氯苯基环丙基酮肟-O-(3-苯氧基苄基)醚,产率80%。  相似文献   

8.
离子液体中V2O5催化环己烯选择氧化合成 2-环己烯酮   总被引:1,自引:0,他引:1  
研究了以V2O5为催化剂,H2O2为氧化剂,在室温离子液体中环己烯氧化制备2-环己烯酮的反应.考察了离子液体种类、反应温度、催化剂用量和氧化剂用量等因素对2-环己烯酮产率的影响.结果表明,在H2O2用量为110 mmol,V2O5/环己烯摩尔比为2%,反应温度为313 K的条件下,在[bmim]BF4离子液体中反应10 h后,环己烯的转化率和2-环己烯酮选择性分别为88.7%和91.1%.对含离子液体的催化体系的重复使用性能进行了考察.结果发现,随着使用次数的增加,环己烯的转化率以及2-环己烯酮的选择性有所下降.  相似文献   

9.
采用水热法合成了Ti-MCM-41分子筛,XRD、FT-IR、ICP-AES以及DRS-UV-Vis表征结果表明几乎所有的Ti均进入具有MCM-41结构的分子筛骨架中。所合成的Ti-MCM-41对环己烯催化环氧化反应具有较优异的催化性能。溶剂种类、Ti-MCM-41催化剂用量、环己烯/H2O2比、反应温度等工艺条件对Ti-MCM-41催化性能的影响考察表明,在催化剂用量23.33g/L、环己烯浓度2.67mol/L、H2O2浓度0.67mol/L、10mL乙腈为溶剂、70℃反应180min条件下,环己烯单程转化率及H2O2有效利用率最高分别可达23.85%和95.04%。  相似文献   

10.
8-羟基喹啉对V2O5催化氧化环己烯的调变作用   总被引:1,自引:0,他引:1  
研究了8-羟基喹啉对丙酮中V2O5催化氧化环己烯合成环己烯酮的调变作用,考察了8-羟基喹啉的用量、反应温度、反应时间、溶剂和催化剂用量对环己烯氧化反应的影响,发现在该催化体系中生成的环己烯醇和环氧环己烷可转化成环己烯酮,在适当的反应条件下可抑制环己烯醇和环氧环己烷的生成.结果表明,当五氧化二钒的用量为1%,五氧化二钒与8-羟基喹啉之比为1∶2,在20℃以下反应时,过氧化氢几乎定向地将环己烯氧化成环己烯酮.认为是8-羟基喹啉与钒的配位作用促进了环己烯酮的生成.  相似文献   

11.
12.
建立了同时分离测定水杨酸、肉桂酸、阿魏酸和香草酸的电堆集富集-非水毛细管电泳(NACE)的新方法。运行缓冲溶液为40mmol/L乙酸钠-2.5mmol/L氢氧化钠甲醇溶液,电压-25kV,在225nm波长下紫外检测。对电压、乙酸钠浓度、氢氧化钠浓度、进样时间、样品溶液等因素对电堆集及分离的影响做了系统的研究。水杨酸、肉桂酸、阿魏酸和香草酸分别在1.4~28mg/L、0.40~8.0mg/L、0.7~18mg/L和0.7~30mg/L范围内线性关系良好(r=0.9999、r=0.9997、r=0.9994、r=0.9997);回收率分别为95.8~99.6%、96.2~98·2%、95.7~105%和98.9~103%,基于3倍信噪比(S/N=3),4种有机酸的检出限分别为0.069、0.051、0.107和0.089mg/L。  相似文献   

13.
离子色谱法测定乙醛酸中的顺丁烯二酸和乙二酸   总被引:1,自引:0,他引:1  
采用抑制电导离子色谱法测定高浓度乙醛酸基体中痕量的顺丁烯二酸和乙二酸。将乙醛酸样品稀释至1 000倍体积后,采用高浓度的淋洗液,以高容量色谱柱对样品进行分析。实验结果表明,顺丁烯二酸和乙二酸最低检出限分别为12.7,19.6μg/L,重现性(n=5)分别为1.13%,1.11%,回收率分别为97.9%,94.7%。该方法具有较高的灵敏度,适用于乙醛酸的例行检测。  相似文献   

14.
《Analytical letters》2012,45(12):2265-2277
Abstract

An analytical procedure for measurement of cyanuric acid or trichlor oisocyanuric acid in air has been developed. The procedure involves air sampling with a 37-mm PVC membrane filter, recovery with a phosphate buffer, and analysis by high performance liquid chromatography with a UV detector at 225 nm. The interior surface of the front piece of the cassette filter holder also is analyzed. Average recoveries were 0.98 to 1.00 after fortification of PVC filters with 12- to 412-μg quantities of cyanuric acid. Average recoveries of trichloroisocyanuric acid were 0.83 to 0.98 after fortification of glass surfaces with 12- to 424-μg quantities (these are reasonable approximations for recoveries of trichloroisocyanuric acid from PVC filters). The analyst should ascertain which analyte is present at the sampling site because trichloroisocyanuric acid reacts with water in the phosphate buffer to form cyanuric acid in high yield.  相似文献   

15.
综述了以对硝基苯甲酸为原料合成对氨基苯甲酸的近期研究进展。并从技术和经济角度讨论了各种合成方法的优点与不足。  相似文献   

16.
New magnetically recoverable solid acid catalysts for acid‐catalyzed reactions were designed via the surface chemical functionalization of silica‐coated magnetite nanoparticles (SCMNPs) with sulfonic acid groups. First, the SCMNPs were covalently functionalized with 3‐aminopropyl groups to achieve Amp‐SCMNPs. Then, reaction of the Amp‐SCMNPs with 1,4‐butane sultone followed by acidification with phosphotungstic acid (HPW) or diluted sulfuric acid produced magnetically recoverable solid acid catalysts, HPW‐ampsul‐SCMNPs and H‐ampsul‐SCMNPs, respectively. Both catalysts were characterized by various physicochemical analyses such as Fourier transform infrared (FT‐IR) and inductively coupled plasma‐optical emission (ICP‐OES) spectroscopies, vibrating sample magnetometry (VSM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X‐ray diffraction (XRD), and energy‐dispersive X‐ray (EDX) analyses. Finally, the catalytic activities of the prepared catalysts were examined in the esterification of acetic acid with butanol and acetalization of benzaldehyde with ethylene glycol. Excellent catalytic efficiencies were obtained in both cases. The catalysts were consecutively recovered and reused five times without significant loss of their activities.  相似文献   

17.
本文研究了用对甲基苯磺酸作为淋洗液测定液相中HCOO~-和CH_3COO~-的离子色谱条件,该方法对HCOO~-和CH_3COO~-的最低检出限分别为48ppb和93ppb。该方法与用进口的辛磺酸作为淋洗液的方法进行了对比实验,并用于两广实际酸雨样品中甲酸和乙酸的测量。  相似文献   

18.
A complex between deoxycholic acid (DCA) and salicylic acid (SA) was prepared by grinding and coprecipitation methods. The resultant complex was characterized by means of powder X-ray diffractometry, IR spectroscopy and thermal analysis. The stoichiometry (DCA : SA 1 : 1) of the complex obtained by grinding was identical to that obtained by coprecipitation. The powder X-ray diffraction pattern of the DCA–SA complex differed from the typical pattern of DCA–guest complexes such as DCA–camphor and DCA–phenanthrene complexes. IR spectra suggested that a different kind of hydrogen bonding was formed in the crystal of the DCA–SA complex, compared with the other DCA–guest complexes. This was in good agreement with data from the crystal structure.  相似文献   

19.
硝酸氧解法提高泥炭中黄腐酸的产率   总被引:6,自引:0,他引:6  
何云龙  刘大强 《应用化学》2003,20(12):1220-0
硝酸氧解法提高泥炭中黄腐酸的产率;腐植酸;硝酸氧化降解  相似文献   

20.
An ion chromatographic method is described for the purpose of quality control in the process of monochloroacetic acid production. Using 2.5 mM NaOH–10% methanol as eluent, the simultaneous determination of acetic acid, monochloroacetic acid, dichloroacetic acid, and Cl was obtained in a single run. Monochloroacetic acid and dichloroacetic acid showed good linearity in the range 0.1–20 and 0.15–20 μg/ml and correlation coefficients were 0.9999 and 0.9998, respectively. The detection limits (signal-to-noise ratio 3:1) of monochloroacetic acid and dichloroacetic acid were 17 and 25 ng/ml. This simple, sensitive, and time-saving method can be applied for composition analysis in acetic acid chlorination production.  相似文献   

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