共查询到17条相似文献,搜索用时 171 毫秒
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电氧化合成2-吡啶甲酸 总被引:5,自引:1,他引:4
以2-甲基吡啶为原料,用电化学方法合成了2-吡啶甲酸.研究了反应温度、硫酸浓度、反应物2-甲基吡啶浓度和阳极电位对选择性和电流效率的影响.结果表明,在最佳反应条件下,以电化学方法合成2-吡啶甲酸的选择性高达95.3%,电流效率可达到45.3%. 相似文献
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将迭代算法、PLS与紫外吸收光谱法相结合,建立了同时测定二甲苯间接电合成甲基苯甲醛混合6组分中3种甲基苯甲醛含量的新方法。该方法将PLS镶嵌在迭代算法内部,通过多次迭代计算逐步逼近样品真值,提高了光谱的识别能力。将该方法用于4组模拟样本的测定,邻、间、对甲基苯甲醛的平均回收率分别为101%、100%和101%,预测均方差(RMSEP)分别为0.214、0.148和0.057。而应用于5批实际电合成产物中3种甲基苯甲醛同分异构体的同时测定,邻、间、对甲基苯甲醛的平均回收率分别为106%、92%和100%,相对偏差≤±19.7%,与高效液相色谱法测定结果基本吻合。 相似文献
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将间接电合成苯甲醛与电还原马来酸制备丁二酸的过程有机结合, 构建了一个新的成对电解体系, 即在隔膜电解槽中, 以纯Pb为阴极, PbO2/Pb为阳极, 硫酸溶液为介质, 在施加超声波的条件下, 阳极氧化Ce3+为Ce4+, 阴极还原马来酸生成丁二酸; 同时, 在槽外采用Ce4+氧化甲苯生成苯甲醛. 实验结果表明, 阴极和阳极电解的平均电流效率分别为92.71%和87.81%, 总的电流效率高达180.52%; 且Ce4+槽外氧化甲苯为苯甲醛的收率为95.78%, 马来酸电还原为丁二酸的转化率为92.09%; 电解的槽电压与单一电解氧化Ce3+相比降低了0.25 V. 相似文献
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在石墨电极上直接电氧化合成D—阿拉伯糖 总被引:1,自引:0,他引:1
报导了用伏安法和恒电位电解法在光谱石墨电极上直接电氧化 D-葡萄糖酸钠合成 D-阿拉伯糖的研究结果。研究了 D-葡萄糖酸钠浓度、施加电压、温度、支持电解质对合成 D-阿拉伯糖的产率、电流效率的影响.最后用流动液体电解池作实验室规模的电合成获得成功,并用正交实验法优选出了最佳电合成的工艺条件。电解后电解液产物的分析结果表明,生成 D-阿拉伯糖的选择性为100×10~(-2),电流效率大于80×10~(-2)。 相似文献
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通过电解实验分别考察了5个阴极电还原反应和1个阳极电氧化反应在加入添加剂前后电流效率和转化率的变化。所选择的6个反应可以分为2类,一类是原料以分子形式存在于电解液中的反应,另一类是原料以离子形式存在于电解液中的反应。实验间二硝基苯电还原制间苯二胺,3-甲基吡啶氧化制烟酸和邻硝基酚电还原制邻氨基酚(酸性条件下)属于前一类反应,加入添加剂后,它们的电流效率分别由原来的65.69%、28.00%和45.09%变为66.15%、28.45%和37.07%,说明添加剂对原料以分子形式存在的反应没有作用或有抑制作用。实验邻硝基酚电还原制邻氨基酚(碱性条件下),丁二酸的电解全盛和水杨酸电还原制水杨醛属于后一类反应,加入添加剂后,它们的电流效率分别从原来的49.37%、65.06%和24.55%提高到75.80%、78.60%和30.06%,说明添加剂能够提高原料以离子形态存在的反应的电流效率。 相似文献
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In the paper, graphene acid (GA) was manufactured, using flake graphite as raw material, and the acidity and the structure of GA were characterized as well as. Then, chalcone was synthesized in the presence of GA, using acetophenone and benzaldehyde as the reactant. The results showed that the acidity of GA was for pH = 1.12 in aqueous solution, and it was structured by the graphene sheets with the spaces between the graphene sheet and the graphene sheet and sulfuric acid (H2SO4) and acetic acid (CH3CO2H) inside the spaces. At the same time, the results also exhibited that the chalcone yield was able to reach 60.36% when GA dosage was 5 g, and the chalcone yields could attain apart 60.36, 52.05 and 31.16% when 5 g of GA was used thrice. This shows that GA is not only a high-performance catalyst, but also a controlled-release catalyst. 相似文献
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Fan Wang Gaoquan Shi Fengen Chen Jingkun Xu Jiaxin Zhang 《Journal of Electroanalytical Chemistry》2001,510(1-2)
Thianaphthene has been electrochemically polymerized in pure boron trifluoride diethyl etherate (BFEE) solution or in a mixed electrolyte of BFEE and concentrated sulfuric acid (SA). The addition of a certain amount of sulfuric acid into BFEE accelerated the polymerization and also increased the current efficiency of the electrosynthesis. Poly(thianaphthene) (PTN) in the dedoped state is soluble in usual strong polar organic solvents such as dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF) and N-methyl pyrrolidinone (NMP). Its structure has been examined by infrared, H1-NMR and UV spectra. Fluorescent spectral studies indicate that the polymer is a strong blue light emitter. 相似文献
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In this study,the disposable facial tissues derived carbon aerogels(DFTs-CAs)were synthesized using disposable facial tissues as the raw material for fabricating a sensitive amperometric ascorbic acid(AA)sensor.The experimental results indicated that compared to glassy carbon electrode(GCE)and the popular carbon nanotubes modified GCE(CNTs/GCE),DFTs-CAs modified GCE(DFTs-CAs/GCE)exhibited better electrocatalytic activity(i.e.,lower peak potential and higher peak current)for AA electrooxidation and higher analytical performance for AA determination(i.e.,wider linear range,higher sensitivity and lower detection limit),which could be most likely due to the high density of defective sites and large specific surface area of DFTs-CAs.Especially,the DFTs-CAs/GCE was used for evaluating the AA level in real samples(i.e.,medical injection dose,vitamin C tablets,fresh orange juice and human urine)and the results are satisfactory. 相似文献
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M. Dolores Otero 《Tetrahedron letters》2006,47(13):2171-2173
This letter shows a first approximation to the use of CO2 anion-radical in the obtention of α-methyl and α-ethylcyanoacetic acids from propionitrile and butyronitrile, respectively, through a paired electrochemical reaction with CO2. The electrosynthesis of α-chloro-phenylacetic acid from benzyl chloride and phenylacetic acid from toluene by another proposed pathway is also discussed. 相似文献