Bronsted-Lewis双酸性离子液体催化合成乙酸正丁酯

以3-氨基-1-丙磺酸、氯化锌、盐酸为原料制备了一系列Bronsted-Lewis双酸性离子液体。离子液体中磺酸基提供Bronsted酸性,阴离子提供Lewis酸性。采用FTIR、1HNMR、13CNMR、元素分析对合成的离子液体进行了结构表征;对离子液体的Bronsted酸性、Lewis酸性、腐蚀性进行了测定。使用该离子液体催化合成了乙酸正丁酯并利用响应曲面法考察了最佳反应条件。结果表明,在反应温度103℃,催化剂[NH3C3H6SO3H]Cl/0.75ZnCl2(0.75代表3-氨基-1-丙磺酸盐酸盐与氯化锌物质的量比为1.00∶0.75)用量为正丁醇质量的10.03%,n(乙酸)∶n(正丁醇)=1.00∶1.22,反应时间4.92 h,带水剂环己烷用量为正丁醇质量的20%条件下,乙酸正丁酯收率可达97.28%。[NH3C3H6SO3H]Cl/0.75Zn Cl2重复使用5次后,催化剂活性没有明显降低。

Construction of a Bronsted-Lewis solid acid catalyst La-PW-SiO_(2)/SWCNTs based on electron withdrawing effect of La(Ⅲ)onπbond of SWCNTs for biodiesel synthesis from esterification of oleic acid and methanol

A novel solid Bronsted-Lewis acid catalyst La-PW-SiO_(2)/SWCNTs(single-wall carbon nanotubes)was synthesized from the synergistic modification of H_(3)PW_(12)O_(40)(HPW)by single-walled carbon nanotubes functionalized with sidewall hydroxyl groups(SWCNTs–OH)and La^(3+) via sol–gel method.The freshly prepared catalyst was characterized by several methods,and the catalytic activity and stability of it were studied from the esterification of oleic acid and methanol.Results showed that the highest conversion of oleic acid was 93.1%(mass)and maintained as high as 88.7%(mass)after six cycles of La-PW-SiO_(2)/SWCNTs.The high catalytic activity and stability of La-PW-SiO_(2)/SWCNTs can be attributed to the strong electron withdrawing effect of La^(3+) on π bond of SWCNTs,because it can facilitate the formation of a large number of strong Lewis acid sites.Therefore,the reduction of catalytic activity of a solid acid catalyst due to the fact that hydration reaction of its Bronsted acid sites can be effectively reduced.La-PW-SiO_(2)/SWCNTs can be an efficient and economical catalyst,because it shows good catalytic activity and stability.

Synthesis and Characterization of Novel Bronsted-Lewis Acidic Ionic Liquids

To meet the demands of some kinds of reactions catalyzed simultaneously by Br?nsted acid and Lewis acid catalyst, two novel Br?nsted-Lewis acidic ionic liquids, 1-carboxyethylene-3-(4-zinc acetate sulfobutyl) imidazolium chloride ([CH3COO-Zn-O3S-bim-CH2CH2COOH]Cl) and 1-(1,2-dicarboxy) ethylene-3-(4-zinc acetate sulfobutyl) imidazolium chloride ([CH3COO-Zn-O3S-bim-C4H5O4]Cl) were synthesized, in which both Br?nsted and Lewis acidic sites existed in the cation. The structures of the ionic liquids were determined by means of FT-IR, 1H NMR and elemental analysis. The results of Py-IR analysis indicated that the two novel ionic liquids have both Br?nsted and Lewis acid properties. The acid strength values (H0) of the ionic liquids were measured utilizing the UV-visible spectroscopy combined with Hammett indicator method, and the acid amount of them was determined by acid-base titration.

酸性离子液体催化Friedel-Crafts烷基化反应研究进展

介绍了Friedel-Crafts烷基化反应的催化反应机理,综述了Lewis酸性离子液体、Bronsted酸性离子液体、Bronsted-Lewis双酸性离子液体的结构特性及其在催化Friedel-Crafts烷基化反应中的应用研究进展,并对未来发展方向进行了总结和展望。

Br?nsted-Lewis酸性离子液体催化合成乙酸正丁酯

合成了[HO3SC3-NEt3]Cl,与ZnCl2、FeCl3、AlCl3、CuCl2配位制备Bronsted-Lewis酸性离子液体[HO3SC3-NEt3]XCln+1,通过傅里叶变换红外光谱和核磁氢谱对[HO3SC3-NEt3]Cl结构进行表征。利用Bronsted-Lewis酸性离子液体催化合成乙酸正丁酯,通过对各种离子液体的腐蚀性和催化性能的综合分析。结果表明,当以[HO3SC3-NEt3]ZnCl3为催化剂,醇酸摩尔比为1∶1.2,催化剂用量为5%(以正丁醇计量),反应温度为95℃,反应时间为4h,环己烷为带水剂时,乙酸正丁酯的收率可达到96.94%。

Br?nsted-Lewis双酸型离子液体负载浓硫酸催化制备烷基化汽油

设计合成了稳定性良好的Br?nsted-Lewis双酸型离子液体(3-磺酸)-丙基三乙基铵氯锌酸盐-[HO3S-(CH2)3-NEt3]Cl-Zn Cl2,并负载浓硫酸应用于催化异丁烷和异丁烯烷基化反应制备烷基化汽油。结果表明,负载少量浓硫酸的离子液体[HO3S-(CH2)3-NEt3]Cl-Zn Cl2对烷基化反应具有良好的催化性能,在离子液体[HO3S-(CH2)3-NEt3]Cl-Zn Cl2(n([HO3S-(CH2)3-NEt3]Cl)∶n(Zn Cl2)=1∶2)3.0 g,去离子水1.3 g,浓硫酸0.3 g,HC(异丁烷和异丁烯混合物)11.5 g,烷烯摩尔比为10∶1,反应温度40℃,反应时间1 h的较佳反应条件下,异丁烯转化率达到99.6%,三甲基戊烷TMP、二甲基己烷DMH和C9+(碳链超过9个碳的烷烃)选择性分别为84.8%,1.2%和14.0%。催化体系重复使用5次,异丁烯的转化率以及产物的选择性没有明显变化,表明催化剂具有良好的重复使用性能。

功能化Br?nsted-Lewis酸性离子液体催化合成1-氨基烷基-2-萘酚

合成了Br?nsted-Lewis酸性咪唑离子液体[CH_2COOHmim]Fe Cl_3Br,并研究了该离子液体作为催化剂,将2-萘酚、芳香醛、酰胺3组分在无溶剂条件下于100℃下合成一系列的1-氨基烷基-2-萘酚。产物用IR、1HNMR、1 3CNMR对其结构进行确认。实验结果表明,催化剂离子液体可经过5次循环使用,收率保持在90%及以上。