固体酸S2O82-/Nb2O5/La3+的制备、表征及催化合成乙酸正丁酯

以Nb₂O₅为载体,浸渍法研制固体酸（S₂O₈^2-/Nb₂O₅/La⁺）催化剂,经SEM、XRD和EDS表征,考察了固体酸的焙烧温度、陈化时间及S₂O₈^2-浓度等因素对该催化剂催化活性的影响。结果表明：在(NH₄)₂S₂O₈浓度为1 mol/L、浸渍时间18 h、w(La³⁺)=3%（基于Nb₂O₅的质量）、焙烧温度为500 ℃时,制备出最高催化效果的催化剂。接着考察了其催化合成乙酸正丁酯的催化活性,通过正交实验确定了反应的最佳条件：n(正丁醇)/n(冰醋酸）=2.0/1.0、催化剂用量w（S₂O₈^2-/Nb₂O₅/La³⁺）=2.9%（基于反应物质量）、反应温度为125 ℃,反应时间为3.0 h,酯化率为95.70%。催化剂循环利用3次后仍有90.1%的酯化率。      

柱层析硅胶固载K2CO3催化合成生物柴油的研究

研究了柱层析硅胶-K₂CO₃固体碱催化剂的制备条件,并对其进行XRD、FT-IR和SEM表征分析。结果表明,部分K₂CO₃吸收空气中的CO₂生成KHCO₃,K₂CO₃与 KHCO₃分散到硅胶表面,增强了催化效果。并考查了催化剂用量、醇油摩尔比、反应时间对生物柴油制备的影响。研究表明,催化剂的制备温度为120℃,催化剂用量为原料油质量的5%,醇油摩尔比为12∶1,反应温度70℃,反应时间2h,生物柴油收率可达95.2%。     

环境友好催化剂TiSiW12O40/TiO2的制备及其催化性能研究

制备了新型固载杂多酸盐TiSiW12O40/TiO2环境友好催化剂,并以丁酸丁酯的合成作为探针反应,系统考察了原料H4SiW12O40@xH2O与TiO2摩尔比、焙烧温度、焙烧时间等制备条件对TiSiW12O40/TiO2催化活性的影响.实验表明:制备催化剂的适宜条件为原料H4SiW12O40@xH2O与TiO2摩尔比为0.47,焙烧温度为350℃,焙烧时间为3.0 h.利用该条件下制备的催化剂TiSiW12O40/TiO2合成丁酸丁酯,正丁醇与正丁酸的投料摩尔比n(醇):n(酸)=1.3:1,催化剂的用量占反应物总投料质量的1.3%,反应时间为1 h,丁酸丁酯的产率为97.2%.该催化剂TiSiW12O40/TiO2用于制备其它丁酸酯类(如乙酯、丙酯、戊酯、异戊酯)时同样取得了好的结果.     

ZrO_2-TiO_2/SO_4~(2-)催化合成马来酸二异戊酯

以马来酸酐和异戊醇为原料,复合型固体超强酸ZrO2-TiO2/SO24-为催化剂催化合成了马来酸二异戊酯。最佳工艺条件为:催化剂活化温度450℃,活化时间5 h,1.0 mol.L-1H2SO4,催化剂用量1.0 g,酸醇摩尔比为1∶4,回流分水70 m in,酯化率达98.72%。ZrO2-TiO2/SO42-具有良好的催化活性,可重复使用5次以上。     

SO42-/ZrO2的制备工艺对催化橡胶籽油裂解油酯化的影响

以SO₄^2-/ZrO₂为催化剂对橡胶籽油裂解油进行甲酯化。研究了锆源、焙烧温度及焙烧时间对催化剂活性的影响,分别采用氨气吸附程序升温脱附(NH₃-TPD)和吡啶红外(Py-IR)对固体酸SO₄^2-/ZrO₂的酸性和酸型进行分析。实验结果表明,以ZrOCl₂为锆源,550℃焙烧4 h所得固体酸SO₄^2-/ZrO₂的催化活性最好,性能较稳定。对酯化产物的组成及性能进行了考察,结果表明,酯化产物的各项性能均优于传统工艺制备的生物燃油,且与0^#柴油相近。     

钒钼杂多酸盐相转移催化环戊烯氧化制备戊二醛

设计合成了一系列含高价态钼、钒等金属的杂多酸类相转移催化剂,用于催化环戊烯(CPE)氧化制备戊二醛的反应,筛选出催化活性最优的咪唑基钼钒酸盐催化剂[C₄H₉N₂C₃H₃(CH₃)]₅VMo₇O₂₆,并对溶剂种类、H₂O₂用量、催化剂用量、反应温度、时间等进行了条件优化.在优化的反应条件[V(乙酸乙酯)∶V(水)=4∶1,n(Cat.)∶n(H₂O₂)∶n(CPE)=1∶170∶41.6,50℃,6 h]下,得到了88.7%的环戊烯转化率和62.1%的戊二醛选择性,并且催化剂在经过7次循环使用后仍能保持较高的催化活性.     

以固体超强酸SO4^2-／ZrO2-Fe2O3催化合成醋酸异戊酯

以合成醋酸异戊酯为探针反应,筛选出制备固体超强酸SO2-4 /ZrO2- Fe2O3 (SZF -1 )的最佳工艺条件为:ZrOCl2·8H2O9. 7g, FeCl3·6H2O16. 2g, 常温陈化24h, 0. 5mol·L-1 H2SO4 (15mL·g-1 )浸泡5h, 550℃焙烧3h。以SZF 1为催化剂合成醋酸异戊酯的反应条件为:异戊醇200mmol, n(异戊醇)∶n(醋酸) =1. 0∶1. 3, SZF -1 1g(反应物总质量的3% ), 环己烷15mL, 回流反应3h, 酯化率93. 47%。催化剂连续使用6次后酯化率仍在70%以上。     

纳米复合固体超强酸S_2O_8~(2-)/CoFe_2O_4催化合成癸二酸二乙酯

将硫酸钴、硫酸亚铁在NaOH溶液中与NaHCO3反应制得碱式碳酸盐前驱体 ,后者用 (NH4 ) 2 S2 O8浸渍、干燥 ,再经 5 0 0℃焙烧得到固体超强酸催化剂S2 O2 -8/CoFe2 O4 。产物经XRD、TEM、BET、TG DTA及化学法等检测 ,含硫量 4 5 2 % ,粒径为 4 2nm ,比表面积为 1 4 6m2 /g ,粒度均匀。催化剂的酸强度处于 -1 6 0 2和-1 4 5 2之间。以该固体酸为催化剂 ,由癸二酸和无水乙醇合成了癸二酸二乙酯。最佳反应条件为 :n(醇 )∶n(酸 ) =4 0∶1 0 ,癸二酸 0 1mol,催化剂 1 0 g ,反应时间 2 5h。在此反应条件下 ,酯化率可达 93 6%。     

固体超强酸SO2-4/TiO2-SnO2的制备、表征及催化合成D, L-丙交酯

采用沉淀法在不同工艺条件下制备了稀土改性的新型固体超强酸SO2-4/TiO2-SnO2催化剂, 考察了其对D, L-乳酸合成D, L-丙交酯的催化活性, 并通过Hammett指示剂法测定了催化剂的酸强度, 用FT-IR和FT-Raman技术考察了焙烧温度、硫酸浸渍液浓度和浸渍时间以及La2O3的负载量对该固体超强酸结构和性能的影响. 研究结果表明: SnO2的存在促进了金红石相TiO2的形成, 在600 ℃焙烧3 h、 3.0 mol/L H2SO4溶液浸渍12 h、 n(Ti4+): n(Sn4+): n(La3+)=1:1:0.05条件下制备的SO2-4/TiO2-SnO2的酸强度最大, 达-13.75以上, 催化合成丙交酯的产率最高(78.4%). 并且考察了催化剂用量对D, L-丙交酯粗产率的影响和催化剂重复使用的性能.     

水介质中高分子配体负载微粒钯催化Suzuki偶联反应

对Wang树脂进行改性,制备了高分子负载纳米钯催化剂,并将其应用于水介质中卤代芳烃与芳硼酸的Suzuki偶联反应。 以溴苯和苯硼酸的偶联反应为模型,考察了溶剂、温度、碱种类、催化剂用量对反应的影响,确定较佳的反应条件为：n(C₆H₅Br)∶n(C₆H₅B(OH)₂)∶n(WRP-Pd)∶n(K₂CO₃)∶n(TBAB)=1.0∶1.5∶0.005∶2.0∶0.5,反应温度100℃, 反应时间4 h。 用氯代芳烃代替溴代芳烃反应时,延长反应时间,也能得到较高产率。 催化剂经过简单的过滤洗涤后,重复使用4次活性无明显降低。     

稀土固体超强酸SO42-/TiO2/La3+催化合成丁酸异戊酯

The synthesis of isoamyl butyrate with isoamyl alcohol and butyric acid as reactants and rare-earth solid superacid SO₄^2-/TiO₂/La³⁺ as catalyst had been studied.The influent actors of reaction were investigated.The results showed that the appropriate conditions should be: Weight of catalyst was 0.5g (weight of butyric acid if 0.2mol); molar ratio of isoamyl alcohol to butyric acid was 1.8: 1; reaction time was 2.0 h; the taking water reagent (Toluene) was 15mL.The yield of isoamyl butyrate was about 99.0%.     

稀土固体超强酸SO42-/TiO2/La3+催化合成丁酸异戊酯

丁酸异戊酯是无色至淡黄色透明油状液体,有近似生梨和香蕉香甜气。天然品存在于椰子油、可可豆、苹果、香蕉、葡萄、草莓等中,是我国ＧＢ２７６０－８６规定允许使用的食用香料,主要用以配制香蕉、菠萝、杏、樱桃和杂锦水果等型香精;也可用作提取天然香料的溶剂、乙酸纤维素的溶剂及增塑剂。通常它是在硫酸催化下由丁酸和异戊醉酯化反应而得［１,２］,反应时间长,副反应多,对设备腐蚀严重,废水排放量大,后处理工艺复杂。为此,本实验选用稀土固体超强酸ＳＯ４２－／ＴｉＯ２／Ｌａ３＋作为催化剂进行某些酸与异戊醇的酯化反应。 …     

Synthesis of butyrate using a heterogeneous catalyst based on polyvinylpolypyrrolidone

A heterogeneous polyvinylpolypyrrolidone supported Brønsted acidic catalyst ([PVPP-BS]HSO₄) was used to synthesize butyrate in this paper. The prepared catalysts were characterized by FT-IR, TG, and FESEM and their catalytic activity in butyric acid esterification with benzyl alcohol was investigated. The influencing factors such as the amount of catalyst, reaction temperature, and reaction time were carefully studied. Under the optimized condition with the butyric acid to benzyl alcohol mole ratio of 1: 1.2 and the reaction temperature of 130°C, the yield of benzyl butyrate reached 96.8 % within 4 h in the presence of 8 mass % of catalyst. Moreover, the catalyst could be reused six times without noticeable drop in activity. This catalyst was also used to synthesize other kinds of butyrates achieving the butyrate yield above 90 %.     

四氯化锡催化乙酸异戊酯的合成

羧酸酯是重要的化工产品 ,其合成一直受到人们的关注 .它一般是利用羧酸、羧酸酐或酰氯与醇反应制得 ,羰基化制酯类近年也颇受重视 [1] .异戊醇是工业废料杂醇油的主要成份 ,如何合理利用是一个急需解决的问题 .一个方便的途径是使其与乙酸反应制备乙酸异戊酯 .乙酸异戊酯在香料、溶剂、萃取剂等方面都有广泛的应用 ,其传统合成方法是利用浓硫酸作为催化剂进行酯化反应 ,存在的缺点是对设备有严重的腐蚀、副产物较多、时间较长等 .四氯化锡作为高效的酯化催化剂引起了我们的注意 [2 ,3] .本文利用四氯化锡作为乙酸异戊酯的合成催化剂 ,在较…     

生物质炭基固体酸催化剂的制备

 以生物质木粉为原料, 采用炭化-磺化法制备了炭基固体酸催化剂, 并用于油酸与甲醇的酯化反应, 考察了制备条件对炭基固体酸催化剂活性的影响. 采用 X 射线衍射、红外光谱、热重分析、高分辨透射电子显微镜及元素分析等手段对催化剂进行了表征. 结果表明, 由生物质木粉制备的炭基固体酸催化剂具有较高催化酯化反应活性, 在 400 oC 下炭化 0.5 h, 135 oC 下磺化 1 h 制备的炭基固体酸催化剂在精馏分水连续酯化装置中催化油酸与甲醇的酯化反应 2 h 时, 酯化转化率达到 96%. 采用炭化-磺化法制备的生物质炭基固体酸催化剂具有蠕虫状的无序乱层炭结构, 磺酸基 (－SO3H) 含量高达 13.25%, 并且在 220 oC 以下时具有良好的热稳定性.     

Aluminum phosphate-based solid acid catalysts: Facile synthesis,characterization and their application in the esterification of propanoic acid with n-butanol

Novel solid acid catalysts synthesized from aluminum phosphate were prepared via a precipitation method and a subsequent sulfating treatment. Their catalytic performances for the esterification of propanoic acid with n-butanol were investigated. The as-prepared catalysts were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption–desorption, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), temperature programmed desorption of ammonia (NH₃-TPD), infrared spectroscopy of adsorbed pyridine, and other techniques. Experimental results of esterification reactions indicated that the calcination temperature can significantly affect the catalytic performances and the catalyst calcined at 500 °C (SO₄²⁻/AlPO₄-500) exhibited the highest activity. The effects of different reaction conditions including reaction time, reaction temperature, catalyst amount and alcohol/acid molar ratio were studied in detail. The maximum propanoic acid conversion of 91% was achieved under optimum reaction conditions. Furthermore, the as-prepared SO₄²⁻/AlPO₄-500 catalysts were tested for their reusability in repeated reaction cycles and could be effectively regenerated by a simple reactivation method.     

Nanocrystalline sulfated zirconia as an efficient solid acid catalyst for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones

The condensation reaction of 2-aminobenzamide and aldehydes or ketones was investigated in the presence of nanocrystalline sulfated zirconia (SO₄ ^2?/ZrO₂) as solid acid catalyst. SO₄ ^2?/ZrO₂ nanoparticles with different calcination temperatures were prepared and characterized by XRD, FT-IR and SEM techniques. The results confirm good stabilization of tetragonal phase of zirconia in the presence of sulfate. The reusability experiments show partial deactivation of the catalyst due to leaching of the sulfate and coke deposition on the catalyst.     

An efficient and facile procedure for synthesis of octyl polyglucoside

Nonionic surfactant alkyl polyglucoside (APG) was prepared by direct glycosidation of alkyl alcohol with glucose in the presence of sulfate acid-silica gel (H_2SO_4/SiO_2) as solid acidic catalyst.The quantity of catalyst was only of 1 wt%,based on the glucose,and the conversion of glucose was close to 100% at 110℃in 1.5h.The product was characterized by FT-IR,mass and ~1H NMR spectra.The degree of polymerization (DP) of the glucose in the product was 1.37,and critical micelle concentration (CMC) of product was only 0.0104 wt%.     

Biodiesel Production from Waste Cooking Oil over Mesoporous SO42-/Zr-SBA-15

Biodiesel production from waste cooking oils over SO₄^2-/Zr-SBA-15 catalyst was successfully carried out and investigated. SO₄^2-/Zr-SBA-15 catalyst was prepared by one-step process using anhydrous zirconium nitrate as zirconium resource, and endowed with the strong Lewis acid sites formed by supporting the zirconium species onto the SBA-15 surface. The asprepared SO₄^2-/Zr-SBA-15 showed excellent triglyceride conversion efficiency of 92.3% and fatty acid methyl esters (FAME) yield of 91.7% for the transesteriffication of waste cooking oil with methanol under the optimized reaction conditions: the methanol/oil molar ratio of 30, the reaction temperature of 160 oC, the reaction time of 12 h and 10wt% of catalyst. It was noticed that the as-prepared SO₄^2-/Zr-SBA-15 materials with the higher area surface of mesoporous framework and the surface acidity displayed excellent stability and reusability, maintaining high FAME yield of (74±1)% after seven runs of reaction.     

Nanosized sulfated zirconia as solid acid catalyst for the synthesis of 2-substituted benzimidazoles

The condensation reaction of o-phenylenediamine and arylaldehydes was investigated in the presence of nanosized sulfated zirconia (SO ₄ ^2? -ZrO₂) as the solid acid catalyst. Nanosized SO ₄ ^2? -ZrO₂ was prepared and characterized by the XRD, FT-IR, and SEM techniques. The results confirm good stabilization of the tetragonal phase of zirconia in the presence of sulfate. Reusability experiments showed partial deactivation of the catalyst after each run; good reusability can be achieved after calcinations of the recovered catalyst before its reuse.