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TiSiW12O40/TiO2催化合成葡萄糖酯的研究 总被引:56,自引:4,他引:52
《精细化工》2001,18(7):408-410
以固载杂多酸盐TiSiW12O40/TiO2为多相催化剂,对以乙酸酐、丙酸、丁酸、异丁酸和葡萄糖为原料合成葡萄糖酯的反应条件进行了研究.实验表明TiSiW12O40/TiO2是合成葡萄糖酯的良好催化剂,最佳反应条件为n(糖)∶n(酸)=1∶6,催化剂用量为反应物料总质量的2.0%,反应时间为2h.上述条件下,葡萄糖五乙酸酯的产率为88.7%,葡萄糖五丙酸酯的产率为84.5%,葡萄糖五丁酸酯的产率为85.4%,葡萄糖五异丁酸酯的产率为86.4%. 相似文献
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TiSiW_(12)O_(40)/TiO_2催化合成葡萄糖酯的研究 总被引:38,自引:0,他引:38
以固载杂多酸盐TiSiW12 O4 0 /TiO2 为多相催化剂 ,对以乙酸酐、丙酸、丁酸、异丁酸和葡萄糖为原料合成葡萄糖酯的反应条件进行了研究。实验表明 :TiSiW12 O4 0 /TiO2 是合成葡萄糖酯的良好催化剂 ,最佳反应条件为 :n(糖 )∶n(酸 ) =1∶6 ,催化剂用量为反应物料总质量的 2 0 % ,反应时间为 2h。上述条件下 ,葡萄糖五乙酸酯的产率为 88 7% ,葡萄糖五丙酸酯的产率为 84 5 % ,葡萄糖五丁酸酯的产率为 85 4% ,葡萄糖五异丁酸酯的产率为 86 4%。 相似文献
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TiSiW12O40/TiO2催化合成氯乙酸乙酯 总被引:1,自引:2,他引:1
介绍了固载杂多酸盐TiSiW12O40/TiO2催化剂的制备方法.首次以TiSiW12O40/TiO2为多相催化剂,通过氯乙酸和乙醇反应合成了氯乙酸乙酯,并探讨了反应因素对产率的影响.实验表明TiSiW12O40/TiO2具有良好的催化活性,醇酸物质的量比为1.41,催化剂用量为反应物料总量的2.0%,反应时间为2.0h,反应温度为89~96℃,产率可达49.84%. 相似文献
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TiSiW12O40/TiO2催化合成氯乙酸乙酯 总被引:2,自引:2,他引:0
首次以固载杂多酸盐TiSiW12O40/TiO2为多相催化剂,通过氯乙酸和乙醇反应合成了氯乙酸乙酯,并探讨了诸因素对产率的影响,实验表明:TiSiW12O40/TiO2具有良好的催化活性,醇酸物质的量比为1.4:1,催化剂用量为反应物料总质量的2.0%,反应时间2.0h,反应温度89~96℃,产率可达43.02%。 相似文献
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以TiSiW12O40/TiO2为催化剂,对以丙酸和异丁醇为原料合成丙酸异丁酯的反应条件进行了研究。实验表明:TiSiW12O40/TiO2是合成丙酸异丁酯的良好催化剂,适宜的反应条件为:醇∶酸(摩尔比)=1.2∶1,催化剂用量为反应物料总质量的2.0%,反应时间1.0h,反应温度106~125℃。上述条件下,丙酸异丁酯的收率可达79.1%。 相似文献
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TiSiW_(12)O_(40)/TiO_2催化合成丙酸乙酯 总被引:6,自引:0,他引:6
研究了固载杂多酸盐TiSiW12 O40 /TiO2 催化丙酸与乙醇的酯化反应 ,探讨了催化剂用量、反应时间及醇酸摩尔比对酯产率的影响。当醇酸摩尔比为 1 4∶1,催化剂的量为醇酸总质量的 2 0 % ,反应时间为 1 0h ,酯产率可达 5 0 3% 相似文献
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TiSiW12O40/TiO2微波催化合成丁酮乙二醇缩酮 总被引:8,自引:0,他引:8
以TiSiW12O40/TiO2为固相催化剂,通过微波催化丁酮和乙二醇反应快速合成丁酮乙二醇缩酮,较系统地研究了酮醇物质的量比,催化剂TiSiW12O40/TiO2的用量,反应功率和反应时间等诸因素对产品产率的影响。实验表明:TiSiW12O40/TiO2是合成丁酮乙二醇缩酮的良好催化剂,在环己烷为带水剂n(酮)∶n(醇)=1∶1.25,催化剂的用量为反应物总质量的0.5%,反应功率为480 W,反应时间为35 min的优化条件下,丁酮乙二醇缩酮的收率可达87.16%。 相似文献
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Cu2O/TiO2, Bi2O3/TiO2 and ZnMn2O4/TiO2 heterojunctions were studied for potential applications in water decontamination technology and their capacity to induce an oxidation process under VIS light. UV–vis spectroscopy analysis showed that the junctions-based Cu2O, Bi2O3 and ZnMn2O4 are able to absorb a large part of visible light (respectively, up to 650, 460 and 1000 nm). This fact was confirmed in the case of Cu2O/TiO2 and Bi2O3/TiO2 by photocatalytic experiments performed under visible light. A part of the charge recombination that can take place when both semiconductors are excited was observed when a photocatalytic experiment was performed under UV–vis illumination. Orange II, 4-hydroxybenzoic and benzamide were used as pollutants in the experiment. Photoactivity of the junctions was found to be strongly dependent on the substrate. The different phenomena that were observed in each case are discussed. 相似文献
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Surface-phase ZrO2 on SiO2 (SZrOs) and surface-phase La2O3 on Al2O3 (SLaOs) were prepared with various loadings of ZrO2 and La2O3, characterized and used as supports for preparing Pt/SZrOs and Pt/SLaOs catalysts. CH4/CO2 reforming over the Pt/SZrOs and Pt/SLaOs catalysts was examined and compared with Pt/Al2O3 and Pt/SiO2 catalysts. CO2 or CH4 pulse reaction/adsorption analysis was employed to elucidate the effects of these surface-phase oxides.
The zirconia can be homogeneously dispersed on SiO2 to form a stable surface-phase oxide. The lanthana cannot be spread well on Al2O3, but it forms a stable amorphous oxide with Al2O3. The Pt/SZrOs and Pt/SLaOs catalysts showed higher steady activity than did Pt/SiO2 and Pt/Al2O3 by a factor of three to four. The Pt/SZrOs and Pt/SLaOs catalysts were also much more stable than the Pt/SiO2 and Pt/Al2O3 catalysts for long stream time and for reforming temperatures above 700 °C. These findings were attributed to the activation of CO2 adsorbed on the basic sites of SZrOs and SLaOs. 相似文献
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以冰乙酸和异戊醇为原料,Al_2(SO_4)_3/FeCl_3为催化剂,对催化合成乙酸异戊酯的条件进行研究。考察催化剂用量、乙酸与异戊醇物质的量比以及反应时间对乙酸酯化率的影响。结果表明,Al_2(SO_4)_3/FeCl_3具有良好的催化活性,在乙酸物质的量为0.1 mol、乙酸与异戊醇物质的量比为1∶4、催化剂用量1.0 g、反应时间2.0 h和带水剂环己烷用量10 m L反应条件下,重复实验3次,平均乙酸酯化率为93.50%。 相似文献
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稀土固体超强酸SO2-4/TiO2/La3+催化合成醋酸丁酯 总被引:13,自引:0,他引:13
《化学世界》2001,42(12):653-654
研究了以固体超强酸SO24-/TiO2/La3+催化剂,醋酸和正丁醇为原料合成醋酸丁酯,并考察了影响反应的因素.结果表明醇酸物质的摩尔比为1.61、催化剂用量0.6
g、带水剂甲苯7 mL、反应时间2.5 h是最适宜的反应条件,其酯化率可达96.2%. 相似文献
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Free acids of the iron substituted heteropoly acids (HPA), H7[(P2W17O61)FeIII(H2O)] (HFe1) and H18[(P2W15O56)2FeIII2(H2O)2] (HFe2) were prepared from the salts K7[(P2W17O61)FeIII(H2O)] (KFe1) and Na12[(P2W15O56)2FeIII4(H2O)2] (NaFe4), respectively. The iron-substituted HPA were adsorbed on to XC-72 carbon based GDLs to form HPA doped GDEs after water washing with HPA loadings of ca. 1 μmol. The HPA was detected throughout the GDL by EDX. Solution electrochemistry of the free acids are reported for the first time in sulfate buffer, pH 1-3. The hydrogen oxidation reaction was catalyzed by KFe1 at 0.33 V, with an exchange current density of 38 mA/cm2. Moderate activity for the oxygen reduction reaction was observed for the iron substituted HPA, which was dramatically improved by selectively removing oxygen atoms from the HPA by cycling the fuel cell cathode under N2 followed by reoxidation to give a restructured oxide catalyst. The nanostructured oxide achieved an OCV of 0.7 V with a Tafel slope of 115 mV/decade. Cycling the same catalysts in oxygen resulted in an improved catalyst/ionomer/carbon configuration with a slightly higher Tafel slope, 128 mV/decade but a respectable current density of 100 mA/cm2 at 0.2 V. 相似文献
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Qingzhao Li Changsui Zhao Xiaoping Chen Weifang Wu Baiquan Lin 《Chemical Engineering and Processing: Process Intensification》2010
Pulverized coal combustion in O2/N2 and O2/CO2 environments was investigated with a drop tube furnace. Results present that the reaction rate and burn-out degree of O2/CO2 chars (obtained in O2/CO2 environments) are lower than that of O2/N2 chars (obtained in O2/N2 environments) under the same experimental condition. It indicates that a higher O2 concentration in O2/CO2 environment is needed to achieve the similar combustion characteristic to that in O2/N2 environment. The main differences between O2/N2 and O2/CO2 chars rely on the pore structure determined by N2 adsorption and chemical structure measured by FT-IR. For O2/CO2 char, the surface is thick and the pores are compact which contribute to the fragmentation reduction of particles burning in O2/CO2 environment. The organic functional group elimination rate from the surface of O2/CO2 chars is slower or delayed. The present research results might have important implications for further understanding the intrinsic kinetics of pulverized coal combustion in O2/CO2 environment. 相似文献
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The modification of activated carbon fibres prepared from a commercial textile acrylic fibre into materials with monolithic shape using phenolic resin as binder was studied. The molecular sieving properties for the gas separations CO2/CH4 and O2/N2 were evaluated from the gas uptake volume and selectivity at 100 s contact time taken from the kinetic adsorption curves of the individual gases. The pseudo-first order rate constant was also determined by the application of the LDF model. The samples produced show high CO2 and O2 rates of adsorption, in the range 3-35 × 10−3 s−1, and in most cases null or very low adsorption of CH4 and N2 which make them very promising samples to use in PSA systems, or similar. Although the selectivity was very high, the adsorption capacity was low in certain cases. However, the gas uptake in two samples reached 23 cm3 g−1 for CO2 and 5 cm3 g−1 for O2, which can be considered very good. The materials were heat-treated using a microwave furnace, which is a novel and more economic method, when compared with conventional furnaces, to improve the molecular sieves properties. 相似文献
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A solid state metathesis approach has been applied to synthesize perovskite oxides such as BaTiO3, PbTiO3, K0.5Bi0.5TiO3 and Na0.5Bi0.5TiO3, these were characterized by powder XRD, IR and energy dispersive spectra (EDS). Potassium titanium oxalate and metal chlorides are used as the starting materials. X-ray analysis shows the formation of a single phase with tetragonal structure for BaTiO3, PbTiO3, K0.5Bi0.5TiO3 and a monoclinic structure for Na0.5Bi0.5TiO3. The Infrared spectra of these compounds show the characteristic band due to Ti–O octahedron for all the compounds. The EDS spectra show the relative ratio of the metal ions. The morphology of synthesized compounds was obtained from SEM measurements. 相似文献