Preparation, Characterization and Catalytic Activity of Alkyl Benzene Sulfonic Acid Carbon-Based Acid Catalyst

Based on starch and series of alkyl benzene sulfonic acid as the materials, a novel carbon-based solid acid catalyst is synthesized using hydrothermal method. This catalyst exhibits much higher catalytic activity in the reaction of esterification of Mono-fatty alcohol polyoxyethylene maleate esters with 1,4-butanediol. The structure of carbon-based solid acid catalyst was charactered by IR and XRD, characterizations showed that this catalyst exhibited high –SO3H loading. Reusability of the carbon-based solid acid catalyst for esterification showed that after recycling five times the activity remained unchanged.

Effect of Dodecylbenzene Sulfonic Acid Used as Additive on Residue Hydrotreating

The effect of additive—dodecylbenzene sulfonic acid(DBSA)—on residue hydrotreating was studied in the au toclave. The results showed that the additive improved stabilization of the colloid system of residue, which could delay th aggregation and coke formation from asphaltenes on the catalyst, and make heavy components transformed into light oi The residue conversion in the presence of this additive increased by 1.94%, and the yield of light oil increased by 1.53%when the reaction time was 90 min. The surface properties of the catalyst in the presence of this additive were better tha that of the blank test within a very short time(30 min) and deteriorated rapidly after a longer reaction time due to highe conversion and coke deposition. Compared with the blank test, the case using the said additive had shown that the structur of hydrotreated asphaltene units was smaller and the condensation degrees were higher. The test results indicated that th additive could improve the hydrotreating reactivity of residue via permeation and depolymerization, the heavier componen could be transformed into light oil more easily, and the light oil yield and residue conversion were higher for the case usin the said additive in residue hydrotreating process.

Modified graphene‐based materials as effective catalysts for transesterification of rapeseed oil to biodiesel fuel

Production of biodiesel by the transesterification process using different modified graphene‐based materials as catalysts was studied.Solid acid graphene‐based samples were prepared by grafting sulfonic or phosphate groups on the surface of thermally reduced graphene oxide.The obtained materials were thoroughly characterized using scanning electron microscopy,X‐ray diffraction,thermogravimetric analysis,X‐ray photoelectron spectroscopy,N2 adsorption‐desorption measurements,potentiometric titration,elemental analysis,and Fourier transform infrared spectroscopy.The prepared catalysts were tested in the transesterification of rapeseed oil with methanol at 130°C under pressure,and their activities were compared to the performance of a commercially available heterogeneous acidic catalyst,Amberlyst‐15.All modified samples were active in the transesterification process;however,significant differences were observed in the yield of biodiesel,depending on the method of catalyst preparation and strength of the acidic sites.The highest yield of fatty acid methyl esters of 70%was obtained for thermally reduced graphene oxide functionalized with 4‐benzenediazonium sulfonate after 6 h of processing,and this result was much higher than that obtained for the commercial catalyst Amberlyst‐15.The results of the reusability test were also promising.

Sulfonic acid-functionalized mesoporous silica catalyst with different morphology for biodiesel production

Sulfonic acid functionalized mesoporous silica based solid acid catalysts with different morphology were designed and fabricated.The synthesized materials were characterized by various physicochemical and spectroscopic techniques like scanning electron microscopeenergy dispersive X-ray spectroscopy,Fourier transform infrared spectroscopy,Brunauer–Emmett–Teller surface area,thermogravimetric analysis and n-butylamine acidity.The shape of catalysts particles plays an important role in its activity.The sulfonic acid functionalized mesoporous silica catalysts of spherical shape and the cube shape were assessed for catalytic activity in biodiesel production.The catalytic biodiesel production reaction over the catalysts were studied by esterification of free fatty acid,oleic acid with methanol.The effect of various reaction parameters such as catalyst concentration,acid/alcohol molar ratio,catalyst amount,reaction temperature and reaction time on catalytic activity were investigated to optimize the conditions for maximum conversion.It was sulfonated cubic shape mesoporous silica which exhibited better activity as compared to the spherical shape silica catalysts.Additionally,the catalyst was regenerated and reused up to three cycles without any significant loss in activity.The present catalysts exhibit superior performance in biodiesel production and it can be used for the several biodiesel feedstock’s that are rich in free fatty acids.

Imidazolium ionic liquid-supported sulfonic acids:Efficient and recyclable catalysts for esterification of benzoic acid

Several imidazolium ionic liquid（IL）-supported sulfonic acids with different anions,[C_3SO_3Hmim]HSO_4,[C_3SO_3Hmim]BF_4, [C_3SO_3 Hmim]PF_6,and[C_3SO_3Hmim]CF_3SO_3,were synthesized and applied as catalysts for esterification reaction of benzoic acid. The experimental results indicate that imidazolium IL-supported sulfonic acid containing anion of HSO_4^- shows the best catalytic activity.Only when less[C_3SO_3Hmim]HSO_4（0.3 equiv.） applied,was the product obtained with high yield of 97%.Furthermore, the produced esters could be separated by decantation,and the catalyst could be reused after the removal of water.

Sulfonic acid-functionalized core-shell Fe_(3)O_(4)@carbon microspheres as magnetically recyclable solid acid catalysts

Green and recyclable solid acid catalysts are in urgent demand as a substitute for conventional liquid mineral acids.In this work,a series of novel sulfonic acid-functionalized core-shell Fe_(3)O_(4)@carbon microspheres(Fe_(3)O_(4)@C-SO_(3)H)have been designed and synthesized as an efficient and recyclable heterogeneous acid catalyst.For the synthesis,core-shell Fe_(3)O_(4)@RF(resorcinol-formaldehyde)microspheres with tunable shell thickness were achieved by interfacial polymerization on magnetic Fe_(3)O_(4)microspheres.After high-temperature carbonization,the microspheres were eventually treated by surface sulfonation,re sulting in Fe_(3)O_(4)@C-x-SO_(3)H(x stands for carbonization temperature)microspheres with abundant surface SO_(3)H groups.The obtained microspheres possess uniform core-shell structure,partially-graphitized carbon skeletons,superparamagnetic property,high magnetization saturation value of 10.6 emu/g,and rich SO_(3)H groups.The surface acid amounts can be adju sted in the range of 0.59-1.04 mmol/g via sulfonation treatment of carbon shells with different graphitization degrees.The magnetic Fe_(3)O_(4)@C-x-SO_(3)H microspheres were utilized as a solid acid catalyst for the acetalization reaction between benzaldehyde and ethylene glycol,demonstrating high selectivity(97%)to benzaldehyde ethylene glycol acetal.More importantly,by applying an external magnetic field,the catalysts can be easily separated from the heterogeneous reaction solutions,which later show well preserved catalytic activity even after 9 cycles,revealing good recyclability and high stability.

N-Sulfonic acid poly(4-vinylpyridinium) chloride as a highly efficient and reusable catalyst for the Biginelli reaction

A mild, simple and efficient procedure for the preparation of 3,4-dihydropyrimidin-2（1H）-ones and -thiones is described using N-sulfonic acid poly（4-vinylpyridinium） chloride （NSPVPC） as a heterogeneous and efficient catalyst under solvent-free conditions. Simple methodologies, easy work-up procedure, easy preparation of the catalyst, excellent yields and very short reaction times are among the other advantages of this work. Further, the catalyst can be reused and recovered for several times without significant decrease in its activity.

磺化炭催化苯甲酸二甘醇酯化反应制备二甘醇二苯甲酸酯

从精对苯二甲酸(PTA)氧化残渣回收苯甲酸(BA)制备环保增塑剂二甘醇二苯甲酸酯(DEDB),用于替代邻苯二甲酸酯类增塑剂的研究具有重要意义。本工作通过磺化将—SO3H基团负载到活性炭(AC)表面,成功制备了磺化炭(SAC)催化剂。并以BA和二甘醇(DEG)为原料,SAC为催化剂,考察了催化剂浓度、反应温度、酸醇物质的量比[n(BA):n(DEG)]、带水剂甲苯用量对直接酯化合成DEDB的影响。结果表明:原料n(BA):n(DEG)为2.2、催化剂与原料BA的质量比为2%、带水剂甲苯与原料BA的质量比为14%、反应温度为210℃为最佳反应工艺条件,此条件下BA的转化率为90.1%,DEDB的收率为82.6%。

表面含磺酸基的介孔分子筛催化剂SBA-15-SO_3H的制备及其催化性能

采用直接和后合成两种方法制备出含磺酸基的介孔分子筛 SBA-1 5 -SO3 H,用 XRD和红外光谱分析制备过程中催化剂结构和组成的变化 .结果表明 ,两种方法制备出的含磺酸基的催化剂都保持了 SBA-1 5分子筛的完整晶体结构 ,并含有质子酸中心— SO3 H;固体核磁共振表征结果证明 ,两种方法都使 MPTMS存在于分子筛的表面 ;用 N2 吸附 -脱附测定了它们的比表面积、孔径和孔容 ;TGA分析认为 ,MPTMS在分子筛表面的热稳定性大于 30 0℃ ,酸碱滴定结果说明 ,直接法获得的催化剂的酸中心多于后合成法 .酯化反应结果表明 ,直接法合成的催化剂比后合成法具有更高的稳定性 ,且简便、快捷、高效 .

磁性碳基磺酸化固体酸催化剂的制备及其催化水解纤维素

以纤维素和硝酸铁为原料,发烟硫酸为磺酸化试剂,采用热解法合成了磁性碳基磺酸化固体酸催化剂(Fe/C-SO3H).利用扫描电镜(SEM)、透射电镜(TEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)、傅里叶变换红外(FT-IR)光谱仪和振动样品磁强计(VSM)等手段对催化剂进行了表征,评价了催化剂在纤维素水解反应中的催化活性.结果表明,Fe是以γ-Fe2O3的形式存在于碳本体中,催化剂呈现超顺磁性.对于纤维素的水解反应,在优化条件下,纤维素的转化率可达40.6%.此外,催化剂可稳定分散于反应体系中,并在外加磁场作用下可快速与反应体系分离.但催化剂重复使用时催化活性有所下降,其失活原因经初步认定是由于表面部分磺酸基团在反应过程中脱落.

表面含磺酸基的介孔分子筛SBA-15-SO_3H的直接合成

采用水热法直接合成了含磺酸基的介孔分子筛SBA 15 SO3H .XRD表征结果表明 ,该分子筛具有规则的、六方立柱形的中孔结构 ,通过酸碱滴定和XRD确定了正硅酸乙酯 /有机硅的最佳合成配比为 9(α =0 1) .2 9SiMASNMR固体核磁结果表明 ,含磺酸基的有机基团Si (CH2 ) 3 SO3H中的硅与SBA 15骨架上的氧通过Si O键结合 ,形成稳定的有机 /无机组成 ,FT IR谱表明 :在SBA 15 SO3H表面含有质子酸中心 SO3H .N2 吸附 脱附和TEM结果表明 ,SBA 15 SO3H具有较大的比表面积、孔容和孔径 ,孔大小是单一的 ,孔分布是高度有序的 .酯化反应结果表明 ,与后合成法相比 ,直接法合成的催化剂既具有较高的稳定性 ,又具有简便。

对甲苯磺酸催化合成柠檬酸三丁酯

以柠檬酸和正丁醇为原料,对甲苯磺酸为酯化催化剂合成柠檬酸三丁酯(TBC)。结果表明:柠檬酸、正丁醇的摩尔比为1:5,适量催化剂及带水剂苯存在的条件下,酯化率大于98％,产品纯度大于98％;对甲苯磺酸作酯化催化剂时的性能优于用硫酸。用红外光谱表征TBC的结构,并将其添加在聚氯乙烯和氯化聚乙烯树脂中,结果表明,使用TBC作增塑剂,其性能优于邻苯二甲酸二辛酯,且无毒。

介孔分子筛催化剂SBA-15-SO_3H合成ETBE的研究

在强酸性、水热条件下合成表面含磺酸基的介孔分子筛催化剂SBA-15-SO3H。XRD表征结果表明,该分子筛具有规则的六方立柱形的介孔结构;IR法检测到催化剂表面的质子酸中心-SO3H;N2吸附-脱附测定结果表明,该催化剂具有较大的孔径、孔体积和比表面积。在微型固定床反应器内,将该催化剂用于叔丁醇和乙醇合成ETBE的醚化反应,考察了反应温度、原料配比、空速等因素对催化性能的影响。研究结果表明,在温度120℃,空速2 h-1,n(乙醇):n(叔丁醇)=1.5:1.0的条件下,叔丁醇的转化率为64.46％,ETBE的选择性高达83.17％。

Brnsted双核磺酸功能化离子液体催化制备生物柴油

以吗啡啉、1,3-丙烷磺内酯、1,4-二溴丁烷和浓硫酸为原料,通过三步法合成了双-(4-(3-磺丙基)吗啡啉)亚丁基双硫酸氢盐(Bi-[C_3SO_3Hnhm]H_SO_4)双核磺酸功能化离子液体。分别采用FT-IR和TG对合成的离子液体的结构和热稳定性进行表征;同时测定了该离子液体的溶解性、酸性及对奥氏体型不锈钢316的腐蚀性。此外,考察了该离子液体催化大豆油和甲醇反应制备生物柴油的工艺条件中。结果表明,合成的离子液体与目标产物一致,具有较高的热稳定性,能够溶解于极性溶剂,且具有较强的酸性,98%浓硫酸对钢样的腐蚀速率为离子液体的近8倍。当醇油摩尔比为14∶1、离子液体加入量为大豆油和甲醇总质量的5%、反应时间为8 h、反应温度为60℃时,生物柴油的收率为95.4%,且该离子液体经回收、真空干燥,重复使用6次后生物柴油的收率仍然能够达到91.2%。

绿色硝化反应研究进展

介绍了磺酸镧系盐催化硝化、氮氧化物硝化、固体酸催化硝化、液相负载硝化和气相硝化等绿色硝化反应,评述了它们的优缺点,提出了固体氧化物和全氟烷磺酸协同催化NO2/O2绿色硝化反应,有望成为一种有前途的绿色硝化方法。

磺酸功能化钛纳米管催化合成乙酰丙酸正丁酯

以水热法合成的二氧化钛纳米管为载体,将其与3-巯丙基三甲氧基硅烷、双氧水反应,制备了磺酸功能化钛纳米管催化剂(TNTs-SO_3H),采用XRD、FTIR、TEM、TG、UV-Vis及Hammett指示剂法对催化剂的结构和性能进行了表征与测试。以催化合成乙酰丙酸正丁酯为探针反应,考察了TNTs-SO_3H的催化性能。结果表明:当n(乙酰丙酸)∶n(正丁醇)=1∶5、TNTs-SO_3H用量为乙酰丙酸质量的10%、反应温度120℃、反应时间4 h时,乙酰丙酸正丁酯的收率可达86.5%,TNTs-SO_3H重复使用7次后,乙酰丙酸正丁酯收率仍达81.2%。

高比表面积炭基固体酸催化剂的制备及应用

【目的】制备清洁环保且高效的高比表面积炭基固体酸催化剂。【方法】以椰壳基、木粉基、煤基3种活性炭为原料,通过重氮盐还原法制备催化剂,比较3种催化剂的理化性质及性能,以选择最佳的活性炭催化剂。探讨乙醇与油酸物质的量比、反应温度、反应时间、催化剂用量等因素对油酸酯化率的影响,确定油酸酯化反应的最佳条件。【结果】以煤基活性炭制备的催化剂磺酸密度最大(0.64mmol/g),其催化效果也最好,在反应6h后,油酸的酯化率可达69.7%。油酸酯化反应的最佳条件为:乙醇与油酸物质的量比10∶1,反应温度80℃,反应时间12h,催化剂用量为油酸质量的6%,在此条件下,油酸的酯化率可达87.3%。煤基磺化活性炭催化剂在油酸酯化反应中可以稳定地重复使用3次。【结论】以煤基活性炭为原料,用重氮盐还原法可制得高效廉价且清洁环保的炭基固体酸催化剂。

氟离子与磺化反应改性多壁纳米碳管催化剂的制备、表征及催化酯化反应合成油酸甲酯性能

通过高温浸渍法,对多壁纳米碳管进行了氟离子与浓硫酸磺化反应修饰改性处理,制备了一种新型Lewis酸型催化剂F^--SO_4^(2-)/MWCNTs,并通过透射电镜、拉曼光谱、X射线光电子能谱、吡啶吸附红外光谱、X射线荧光光谱、X射线衍射和NH_3程序升温脱附等表征手段对其的物理化学性能进行了表征分析,进而对多壁纳米碳管经F^-与浓硫酸磺化反应修饰改性后所出现的结构与催化性能变化的内在影响规律进行了探索。以F^--SO_4^(2-)/MWCNTs为催化剂,以甲醇和油酸为原料,对其在应用于催化酯化反应合成油酸甲酯过程中的活性进行了研究。结果表明:当反应温度为65℃、醇油物质的量之比为12∶1、催化剂质量占反应物总质量的0.9%、反应时间为6 h,油酸的转化率最高,达到了90%。高催化活性可归因于随着氟元素的加入,提高了SO_4^(2-)的插层作用效果,从而增加了酸性活性位的数量;此外,S=O键具有电子诱导效应,而F^-有强负电性,两者之间发生强烈的相互作用后形成了F^-S键,使S=O的吸电子效应大幅度增强,从而加剧了F^--SO_4^(2-)/MWCNTs催化剂的体系电荷不平衡趋势,导致催化剂中的正电荷过剩,使催化剂中的酸性活性位以Lewis酸为主,有效的避免了单纯磺化反应作用所生成的催化剂的酸性活性位以Br觟nsted酸型为主,而易在富含水的反应介质中发生水合作用而降低,甚至失去催化活性的现象发生。

生物质炭基固体磺酸的制备及其酸催化性能研究

以马尾松木屑为原料,通过炭化、磺化法制备生物质炭基固体磺酸催化剂。通过中和滴定法测定催化剂表面比磺酸量,并应用于油酸与甲醇的酯化反应。以油酸的转化率作为考察指标评价其酸催化活性,考察了制备条件对固体酸催化剂催化活性的影响。采用傅里叶变换红外光谱仪(FTIR)、X射线衍射(XRD)等手段对催化剂进行了表征。通过正交试验确定固体酸催化剂的最佳条件为反应时间2 h;浓硫酸用量100 ml;催化剂用量13%;磺化温度165℃;油酸转化率可达91.36%。

磺化交联壳聚糖树脂固体酸催化剂的制备及表征

壳聚糖是自然界的第二大天然有机物甲壳素的脱乙酰产物,具有来源丰富、环境友好的优点。壳聚糖分子同时含有活泼的氨基和羟基,可通过烷基化、酯化、希夫碱等反应进行化学修饰生成具有各种不同新型结构和功能的衍生物[1]。近年来壳聚糖在催化领域的应用受到了越来越多的关注,