Sulfated Zirconium Catalyst for Synthesis of Dialkylated Diphenylether Disulfonate Gemini Surfactants

Dialkylated diphenylether disulfonate with different alkyl chain lengths (C_n‐DADS, n = 8, 10 and 12) has been synthesized by Friedel‐Crafts alkylation of olefins (C₈, C₁₀ and C₁₂) and diphenyl oxide, followed by sulfonation and neutralization with fuming sulfuric acid. Sulfated zirconia solid acids were prepared and used to catalyze the alkylation reaction. The structure of sulfated zirconia solid acids was identified by infrared spectroscopy. The title compounds were confirmed by infrared spectroscopy and electrospray ionization‐mass spectrometry. Equilibrium surface tension measurements show that the critical micelle concentration (CMC) decreases with an increase in chain length, and the surface tension at CMC (γ_cmc) of C₈‐DADS is the lowest. The minimum area per molecule (A_min) values of C_n‐DADS increase, while the surface excess concentration (Γ_max) values decrease with the increase of the alkyl chain length. C₁₀‐DADS has the highest pC₂₀ and CMC/C₂₀ among C_n‐DADS.     

Esterification of industrial-grade palm fatty acid distillate over modified ZrO2 (with WO3-, SO4 -and TiO2-): Effects of co-solvent adding and water removal

The esterification of palm fatty acid distillate (PFAD), a by-product from palm oil industry, in the presence of three modified zirconia-based catalysts i.e. SO₄-ZrO₂, WO₃-ZrO₂ and TiO₂-ZrO₂ (with several sulfur- and tungsten-loading contents, Ti/Zr molar ratios, and calcination temperatures) was studied. It was found that, among all synthesized catalysts, the reaction in the presence of SO₄-ZrO₂ and WO₃-ZrO₂ (with 1.8%SO₄ calcined at 500 °C and/or 20%WO₃ calcined at 800 °C) enhances relatively high fatty acid methyl ester (FAME) yield (84.9-93.7%), which was proven to relate with the high acid site density and specific surface area as well as the formation of tetragonal phase over these catalysts. The greater benefit of WO₃-ZrO₂ over SO₄-ZrO₂ was its high stability after several reaction cycles, whereas significant deactivation was detected over SO₄-ZrO₂ due to the leaching of sulfur from catalyst. For further improvement, the addition of toluene as co-solvent was found to increase the FAME yield along with reduce the requirement of methanol to PFAD molar ratio (while maintains the FAME yield above 90%). Furthermore, it was observed that the presence of water in the feed considerably lower the FAME yield due to the catalyst surface interfering by water and the further hydrolysis of FAME back to fatty acids. We proposed here that the negative effect can be considerably minimized by adding molecular sieve to remove water from the feed and/or during the reaction.     

Microwave-Assisted Esterification of Oleic Acid Using an Ionic Liquid Catalyst

The combination of 1-butyl-3-methylimidazolium hydrogen sulfate ([Bmim]HSO₄) ionic liquid (IL) and microwave heating was used to esterify oleic acid as a green approach in biodiesel synthesis. To compare the heating systems, conventional heating and the ultrasonic method were employed but the microwave method was found to be more effective. H₂SO₄ and 1-methyl imidazole hydrogen sulfate ([Hmim]HSO₄) were also used in the esterification of oleic acid and their catalytic activities were compared to that of [Bmim]HSO₄. ILs provided some advantages such as reusability, easy recyclability, and very stable activity. There was only a small decrease in the catalytic activity of [Bmim]HSO₄ after four successive applications, which means that ILs can be reused, contrary to homogeneous catalysts. The combination of IL catalysts and microwave irradiation proved to be a potential alternative method for biodiesel production.     

氨基磺酸催化乙酸酯化反应的研究

采用氨基磺酸作催化剂,对乙酸正丁酯合成反应进行了探索性研究。讨论了影响产率的多种因素。最佳条件下乙酸正丁酯产率可达到８８．２％。对其它乙酸酯类物质也进行了合成试验,获得了满意的结果。     

Selective Synthesis of Polyoxyethylene–Polyoxypropylene Block Copolymer (Poloxamer) Fatty Acid Monoesters Over Homogeneous Organotin Catalyst

The synthesis of selected polyoxyethylene–polyoxypropylene block copolymer (poloxamer) fatty acid monoesters is presented. Organotin homogeneous catalyst Sn bis(2‐ethylhexanoate) effectively catalyzed the esterification reaction of (EO)–(PO)–(EO) block copolymer (poloxamer) with fatty acids. The reaction proceeded in high yield and high selectivity to monoesters. Content of diesters in final products was below 1 wt%. The new protocol opened up a high yield and high selective method for the synthesis of poloxamer fatty acid monoesters. These products are potentially interesting for industrial applications, e.g. in lubricants, cosmetics and, in particular, as potential emulsifying agents compatible with hydrocarbon bases, such as paraffin.     

Esterification of Palm Fatty Acid Distillate Using a Sulfonated Mesoporous CuO‐ZnO Mixed Metal Oxide Catalyst

A nanocrystalline mesoporous CuO‐ZnO hollow sphere was successfully fabricated by the hydrothermal method. The nanocomposite was formed in the presence of polyethylene glycol as a dispersant and D‐glucose as a template. The mesoporous CuO‐ZnO catalyst was further functionalized with benzenesulfonic acid to catalyze the esterification of palm fatty acid distillate (PFAD). The physicochemical, textural, structural, and thermal properties of the mesoporous CuO‐ZnO mixed‐oxide catalysts were evaluated. The modified mesoporous catalyst possessed unique textural properties. With a Cu/Zn atomic ratio of 1.0 the best catalytic activity through PFAD esterification was achieved. The optimum reaction conditions in terms of methanol/PFAD molar ratio, catalyst concentration, reaction temperature, and reaction time were determined.     

Synthesis and characterization of fly ash supported sulfated zirconia catalyst for benzylation reactions

Synthesis of highly active nano-crystalline, thermally stabilized solid acid catalyst has been reported by loading different weight fractions of sulfated zirconia on chemically activated fly ash through two step sol-gel technique. The catalysts were characterized using powder XRD, FT-IR, N₂-adsorption desorption study, CHNS elemental analysis, SEM-EDAX and their acidity were measured by pyridine adsorbed FTIR. Liquid phase benzylation of benzene and toluene with benzyl chloride was studied as test reaction for catalytic activity of SZF catalysts. A very high conversion of benzene (87%) and toluene (93%) were observed, which is attributed to significant amount of acid site on the catalyst surface. The FTIR study of the pyridine adsorbed samples reflects the presence of Brønsted as well as Lewis acid sites. The catalyst with 12 wt.% zirconia (SZF-12) was regenerated and reused up to four reaction cycles with equal efficiency as in the first run.     

氨基磺酸的合成和在催化酯化反应中的应用

介绍了氨基磺酸的性质、质量指标及检测方法、各种合成方法及特点 ,并报道了氨基磺酸作为固体强酸催化剂在酯化反应中的应用     

脂肪族戊二酸酯的合成研究

以饱和脂肪酸醇和辽阳石油化纤公司副产物－二羟酸分离出的戊二醇或戊二醇酐为原料，在杂多酸催化下，酯化合成了戊二酸二乙酯（DEG），戊二酸二正丙酯（DPG），戊二酸双丁酯（DBG），戊二酸二正戊酯（DAG），戊二酸二异戊酯（DIAG），戊二酸二异辛酸（DIOG），戊二酸二壬酯（DNG），戊二酸二正癸酯（DDG）共8种化合物，考察了反应温度，反应时间，催化剂用量，反应原料物质的量配比及带水剂用量等对反应的影响，并测定了这些产物的红外光谱，氢核磁共振谱和一些性能指标。     

介孔分子筛SiW12/SBA-15催化合成柠檬酸三丁酯

:将硅钨酸负载在纯硅介孔分子筛SBA-15的表面上,XRD结果表明负载型催化剂SiW12/SBA-15具有纯硅SBA-15的介孔结构.将该催化剂用于合成柠檬酸三丁酯的酯化反应.采用正交实验考察了反应温度、催化剂用量、酸醇摩尔比对柠檬酸转化率的影响,得出最佳反应条件为:反应温度120℃、催化剂用量为总物料质量的1.5%、酸醇摩尔比1:4.在此条件下反应4 h,柠檬酸转化率可达到91.5%,产物的纯度为99.3%.     

微波促进下新型碳基固体酸催化合成草酸酯

在微波辐射条件下,以新型碳基固体酸为催化剂催化草酸分别与正丁醇、异丁醇、正戊醇、异戊醇的酯化反应。系统研究了微波功率、酸醇摩尔比、催化剂用量、反应时间等诸因素对酯化率的影响。实验结果表明：微波功率为500 W,在n（醇）/n（酸）=4.0︰1,催化剂用量占反应物料总质量的2.3%,反应时间为12 min条件下,不同草酸酯的酯化率均在95%以上。该固体酸重复使用多次,其催化活性基本不变。     

Synthesis of Glycerol Triacetate Using a Brønsted–Lewis Acidic Ionic Liquid as the Catalyst

Brønsted–Lewis acidic ionic liquids (IL) were used in the esterification of glycerol and acetic acid to produce glycerol triacetate. The results show that the IL (3–sulfonic acid)–propyltriethylammonium chloroironinate [HO₃S–(CH₂)₃–NEt₃]Cl–[FeCl₃]_x (molar fraction of FeCl₃, x = 0.67) was an efficient catalyst for the esterification reaction. The yield of glycerol triacetate and its content were greater than 98 % when reacted under reflux for 4 h. It was observed that a synergistic effect of Brønsted and Lewis acid sites enhanced the catalytic performance of IL. The reusability of IL was good. After six reaction cycles, the glycerol triacetate yield and concentration were still greater than 98 %. Likewise, the Brønsted–Lewis acidic IL was an efficient catalyst for esterification reactions of high boiling points alcohols with acetic acid.     

HClO4/SBA-15固体酸催化剂的制备及催化性能

将高氯酸引入具有较大孔径和比表面积的介孔分子筛SBA-15中,制备了用于异相催化的固体酸催化剂HClO4/SBA-15,并通过采用X-射线衍射(XRD)、多孔性检测、透射电镜(TEM)分析等方法,对其结构进行了分析表征.HClO4被负载后,材料的比表面积、孔径及孔容等多孔性参数都有所降低,但并没有破坏介孔分子筛SBA-15的孔道结构.为了证明HClO4/SBA-15的催化性能,探究了HClO4/SBA-15催化的选择性脱异丙叉基及乙酰化的一锅法反应.在室温条件和催化量的HClO4/SBA-15作用下,反应30 min内即可完成,产率达到98％,产物的化学结构通过1H NMR、13C NMR及MS等手段得到了表征.该法后处理简单、收率较高,而且不需要任何溶剂.     

新型双孔F-T合成钴基催化剂的制备及其性能

采用浸渍法制备了ZrO2改性的具有2种孔结构的硅胶催化剂载体,以其为基体制备了具有双孔结构的蛋壳型钴基催化剂,考察了其结构和催化性能. 结果表明,双孔结构的载体和相应的催化剂具有更好的比表面性能,ZrO2改性的双孔载体有利于提高催化剂的分散程度、催化活性及C5+选择性. 在温度250℃、压力2 MPa、空速500 h-1条件下,蛋壳型催化剂上CO转化率可达96.6%, C5+选择性为91.2%.     

原位法制备磷钨酸/SBA-15催化剂及其催化性能

用原位合成法制备了不同固载量的磷钨酸催化剂HPW/SBA-15,通过FTIR、TEM、XRD、31PNMR及N2-吸附脱附等方法对催化剂进行表征。结果表明,在低固载量时,原位法制备的催化剂保持了SBA-15材料的长程有序结构,并且随着固载量的提高,孔径、比表面积等均有所下降;固载量达到33.3%时,SBA-15材料的长程有序结构遭到一定的破坏;在载体孔壁中高度分散的磷钨酸仍然保持了Keggin特征结构,且与SBA-15材料的表面羟基存在一定的化学相互作用。对苹果酯合成的催化性能研究表明,乙酰乙酸乙酯的转化率可以达到87%以上,催化剂使用6次后,催化活性仍保持在85%。     

双金属Mo-Ti-SBA-15材料的制备及其环己烯环氧化性能

采用一步法分别制备了一系列单金属介孔催化剂Ti-SBA-15-36,Mo-SBA-15-(180/28)和双金属介孔催化剂Mo-Ti-SBA-15-(X)。考察了双金属催化剂Mo-Ti-SBA-15-(X)的Mo含量,对催化剂的结构和催化性能的影响。分析了催化剂活性差异的原因以及探讨了双金属催化剂的催化协同机理。考察了催化环氧化反应中的主要影响因素。结果表明,最佳的双金属催化剂Mo-Ti-SBA-15-(180/28)的催化效果均优于单金属催化剂的环氧化效果。当反应时间为8 h,反应温度为80 ℃,催化剂剂量为25 mg,以环己烯作为底物,TBHP作为氧源,1,2-二氯乙烷作为溶剂时,Ti-SBA-15-36,Mo-SBA-15-(180/28)和Mo-Ti-SBA-15-(180/28)的转化率分别为41.07%、46.44%和98.33%,选择性分别为97.56%、93.19%和98.86%。同时Mo-Ti-SBA-15-(180/28)也具有很好的可循环利用性。     

Fe-Mo-Ni催化剂的制备及其催化选择氧化制对苯二甲醛

采用溶胶-凝胶法制备了Fe-Mo-Ni三元结构催化剂,以对二甲苯选择氧化为对苯二甲醛(TPAL)为探针反应,研究了该催化剂的制备条件及其催化反应特征,并用热分析(TG-DSC)、X射线衍射(XRD)和紫外漫反射(DRS)对该催化剂进行了分析表征。研究表明,助剂Ni提高了Fe-Mo催化剂的催化活性,使对苯二甲醛的收率由改性前的24.8%提高到38.3%,并且能显著提高催化剂的活性稳定性;影响Fe-Mo-Ni三元结构催化剂的主要因素是Ni的添加量和催化剂焙烧温度,其中Ni的适宜添加量为5%(mol),适宜的焙烧温度为500℃。影响其催化反应的主要因素是空气与对二甲苯流速比和空速,适宜的流速比为150000,适宜的空速为25h-1(对二甲苯流量恒定在0.01mL?min?1):在上述优化的条件下,对二甲苯的转化率为80.3%、对苯二甲醛的选择性为47.7%、对苯二甲醛收率为38.3%。掺入的Ni助剂高度分散在催化剂表面,并参与Mo物种活性中心的形成,使Mo物种的配位和价态发生变化。     

非晶态合金催化剂用于二乙醇胺氧化合成亚氨基二乙酸

采用自制的非晶态合金催化剂进行二乙醇胺氧化合成了亚氨基二乙酸 ,探讨了催化剂用量、反应温度、反应时间、氢氧化钠用量、反应压力等因素对氧化反应的影响 ,确定了最佳工艺条件 ,并考察了催化剂的重复使用效果     

Biodiesel Production from the Lipid of Wastewater Sludge Using an Acidic Heterogeneous Catalyst

The production of biodiesel from the lipid of wastewater sludge was studied using SBA‐15 impregnated with the heteropolyacid H₃PO₄·12WO₃·xH₂O (PW₁₂) as a mesoporous heterogeneous catalyst. X‐ray diffraction, Brunauer‐Emmett‐Teller surface area, thermalgravimetric analysis, and scanning electron microscopy were applied to characterize the prepared catalysts. Catalytic performances were evaluated in a microreactor setup under different experimental conditions. The biodiesel yield for a sample impregnated with 15 % PW₁₂ was 30.14 wt‐% at a temperature of 135 °C and a pressure of 135 psi for 3 h reaction time.     

Al-SBA-15固体酸催化合成硬脂酸三乙醇胺酯

制备了一系列Si/Al比(均为摩尔比,下同)从15到50的Al-SBA-15固体酸催化剂,并将其应用于硬脂酸与三乙醇胺的酯化反应中。结果表明,Si/Al比为25的Al-SBA-15固体酸催化剂的催化活性和选择性较高,反应6 h酯胺的酸值可降至1.78 mg KOH/g,单双酯总质量分数可达84.79%;该催化剂重复使用6次,催化活性没有明显降低,说明该催化剂具有高的稳定性。采用XRD、N2吸附脱附、透射电镜和吸附吡啶的红外光谱对催化剂的结构、比表面积和表面酸性进行了表征,结果表明,Si/Al比为25的Al-SBA-15催化剂保持了SBA-15的结构,具有大的比表面积和均一的孔径,在催化剂表面同时存在Lewis酸和Brnsted酸。