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Glycerol from biodiesel production can be an important industrial feedstock for chemical commodities as it can be used in the food,cosmetic,pharmaceutical and tobacco industries.However,crude glycerol derived from biodiesel production has a low value because of impurities.The purification of this glycerol into a high grade involves high costs and is not economically feasible for small and medium size plants.The glycerol conversion into chlorohydrins was studied using new homogeneous catalysts and hydrochloric acid as chlorination agent.This is an interesting alternative route to epichlorohydrin and then to epoxy resins.The behavior of two series of homologous catalysts,glycolic acid series(glycolic acid,di-glycolic acid and thio-glycolic acid) and amminoacid series(glutamic acid,aspartic acid and cysteine),were investigated for their activity and selectivity.Glycolic acids were more active than amminoacids.The pK_a values had a strong influence on selectivity(mono-chlorohydrins/di-chlorohydrins) for the amminoacid series,which was not observed for the glycolic acids.A kinetic model and reaction mechanism developed in a previous work were used for interpreting the kinetic runs. 相似文献
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Gabriel Morales Juan A.Melero Marta Paniagua Jose Iglesias Blanca Hernandez Maria Sanza 《催化学报》2014,(5)
Sulfonic acid-functionalized heterogeneous catalysts have been evaluated in the catalytic dehydration of C(,monosaccharides into 5-hydroxymethylfurfural(HMF) using dimethyl sulfoxide(DMSO)as solvent.Sulfonic commercial resin Amberlyst-70 was the most active catalyst,which was ascribed to its higher concentration of sulfonic acid sites as compared with the other catalysts,and it gave 93 mol%yield of HMF from fructose in 1 h.With glucose as the starting material,which is a much more difficult reaction,the reaction conditions(time,temperature,and catalyst loading) were optimized for Amberlyst-70 by a response surface methodology,which gave a maximum HMF yield of 33 mol%at 147 °C with 23 wt%catalyst loading based on glucose and 24 h reaction time.DMSO promotes the dehydration of glucose into anhydroglucose,which acts as a reservoir of the substrate to facilitate the production of HMF by reducing side reactions.Catalyst reuse without a regeneration treatment showed a gradual but not very significant decay in catalytic activity. 相似文献
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用 X射线方法测定了二 (对氯苄基 )二氯化锡的晶体结构,该化合物晶体属单斜晶系,空间群为 C2/c,晶体学参数: a=2.8010(3), b=0.4882(2), c=1.2174(3)nm,β =111.71(1)°, V=1.5467(7) nm3, Z=4, Dx=1.893g· cm- 3,μ (MoKα )=23.24cm- 1, F(000)=856.00, R=0.025, Rw=0.038, Sn C键长为 0.2148(3)nm, Sn Cl键长为 0.23754(9)nm。空间构型为畸变四面体构型的单分子有机锡化合物。 相似文献
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借助活性开环聚合反应和紫外光辐照下的分子内交联反应合成新型功能性环状聚(ε-己内酯-co-α-氯代-ε-己内酯)(cP(εCLcoαClεCL)).首先,利用Baeyer-Villiger氧化法将α-氯代环己酮在间氯过氧苯甲酸(mCPBA)的作用下制得功能性单体α-氯代-ε-己内酯(αClεCL).然后,功能性单体αClεCL和ε-己内酯(εCL)在环状引发剂2,2-二丁基-2-锡-1,3-二氧环庚烷(DSDOP)的作用下,进行活性开环聚合反应获得活性环状无规共聚酯(LCP(εCLcoαClεCL))前体,该前体的分子量可以通过改变单体与引发剂的摩尔配比来控制.当单体完全转化后,该活性环状前体再引发反应性单体α-(1-丙烯酰氧乙基)-ε-己内酯(αAEεCL)进行嵌段聚合反应,合成了在活性中心附近带有不饱和双键的功能性环状共聚酯,即活性环状聚(ε-己内酯-co-α-氯代-ε-己内酯)-b-(α-(1-丙烯酰氧乙基)-ε-己内酯).最后该活性环状共聚酯在紫外光辐照下,反应性单体单元中的双键发生分子内交联反应,制得稳定的不含有机锡的新型功能性环状无规共聚酯cP-(εCLcoαClεCL)(M n,NMR=32400).采用SEC,NMR以及DSC等技术对聚合物的结构和性能进行表征,SEC和黏度表征结果显示新型功能性cP(εCLcoαClεCL)与分子量相同的线型共聚酯相比具有较小的动态力学体积,DSC表征结果显示共聚酯环化的结果使其熔点和结晶度下降.该方法的突出特点是能够高效地合成具有高分子量的环状聚合物. 相似文献
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《理化检验(化学分册)》2016,(2)
采用碘量法测定氯乙酸氯化法生产氯乙酰氯产生的废酸液中S2O32-和SO32-的含量。在室温,pH 4~5的条件下直接进行碘量法滴定,测得S2O32-和SO32-的总量;以废酸液中所含SO32-物质的量的3倍加入甲醛,(30±1)℃恒温条件下反应15min以掩蔽SO32-的干扰,用碘量法测得S2O32-的含量,通过计算差值得到SO32-的含量。加标回收率在99.2%~102%之间,测定值的相对标准偏差(n=10)在0.10%~0.20%之间。 相似文献
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The crystal structure of the title complex, [Cu(C23H26N2)Cl2]2·2CH2Cl2, has been determined by single-crystal, X-ray diffraction techniques. The compound crystallizes as dark-green prisms in space group P21/c of the monoclinic system, with Z=4 and unit cell dimensions a=1.710 9(7) nm, b=2.395 2(11) nm, c=1.348 9(6) nm and β=110.651(8)°. The complex consists of two similar but crystallographically independent dimers, of which Cu(Ⅱ) centers display five-coordinated trigonal-bipyramidal geometry with Cu-Cu separations in two centrosymmetric dimers are 0.345 1 and 0.347 8 nm, respectively, and in each dimer the two copper centers share a common edge formed by two bridging chloride ions, each being equatorial. Solvent molecules of CH2Cl2 are packed together in the crystal lattice. CCDC: 253299. 相似文献
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随着人口的不断增长和经济的高速发展,化石燃料(煤、石油和天然气等)的使用量急剧增加,能源短缺、温室效应、环境污染等问题日益严重.因此,发展可再生的清洁能源以取代化石燃料对人类社会的可持续发展至关重.由于氢气具有能量密度高、来源丰富、清洁无毒等优点,有望成为替代化石燃料的最有前景的可再生能源.然而,目前氢气主要来自化石燃料的蒸汽重整,该过程需要高温高压,而且产生的氢气杂质含量高、纯化过程复杂,不能满足绿色化学生产的要求.利用可再生电力电解水制氢是一种绿色高效的制氢方式,但其实际应用受限于动力学过程缓慢的阳极析氧反应(OER).因此,采用动力学过程更快的有机小分子(甲醇、乙二醇、甘油等)氧化反应来替代OER,不仅可以降低制氢能耗,还能在制氢的同时获得高附加值氧化产物.本文采用水热结合高温焙烧法制备了负载于导电碳纸上CuCoN0.6(CuCoN0.6/CP)纳米线催化剂.采用扫描电子显微镜与透射电子显微镜等对催化剂形貌进行表征.结果表明,表面粗糙的CuCoN0.6纳米线组成的纳米小球与碳纸紧密结合.X射线光电子能谱结果表明,C... 相似文献
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《催化学报》2017,(10)
将一系列负载型硅钨酸催化剂用于甘油脱水制丙烯醛反应中.表征结果表明,最终所得催化剂具有高的热稳定性、大的孔径、强的L酸位和大的比表面积.X射线光电子能谱中清晰地出现归属于W(W 4f=35.8 eV),Al(Al 2p=74.9 eV)和Zr(Zr 3d=182.8 eV)元素的谱峰.在SiW_(20)-Al/Zr_(10)催化剂上丙烯醛选择性最高,为87.3%,此时甘油转化率为97%.由于高浓度L酸位的存在,显著降低了催化剂表面积碳量,因而该催化剂即使反应40 h之后仍具有较高地催化生成丙烯醛的活性和选择性.响应面方法表明,在以下优化条件下反应甘油转化率和丙烯醛选择性分别达87.7%和97.0%:催化剂用量0.5wt%,进料甘油浓度10 wt%,反应温度300 ℃.传质限制评估结果显示,当颗粒尺寸d_P20μm时,反应不存在内外扩散限制.综上可见,强L酸催化剂有望用于甘油脱水制丙烯醛反应中 相似文献
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TiO2催化Cr(Ⅵ)-氯代苯酚共存体系中Cr(Ⅵ)的光致还原 总被引:5,自引:0,他引:5
Cr(Ⅵ)离子在TiO2光催化剂表面的暗态吸附,受Cr(Ⅵ)离子浓度及体系酸度的影响较大,4-氯代苯酚(4CP)的存在,对Cr(Ⅵ)离子吸附没有影响。 相似文献
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