介孔磺酸化坡缕石的制备及催化性能

采用后合成方法制备出磺酸官能化的介孔坡缕石固体酸PGS-SO3H催化剂,通过红外光谱,X-射线粉末衍射,扫描电镜和热重等对其进行了表征,并在合成偏苯三酸三辛酯的酯化反应中进行催化性能的评价.单因素考察了催化剂用量,酸醇物质的量比,反应温度等因素对酯化反应的影响.实验结果表明:在反应温度210℃,偏苯三酸酐和2-乙基己醇的物质的量比为1∶4.5,催化剂用量为总反应原料质量的4.9％,反应6h酯化率可达96.16％.     

介孔分子筛的功能化制备及催化性能研究进展

介绍了介孔分子筛经杂原子取代,引入酸功能、氧化还原功能;经有机－无机嫁接（杂合）,引入聚合催化功能、酸催化功能、手性催化功能;经修饰的介孔分子筛,用作固定化酶催化剂的载体;作为催化剂的载体,用于负载过渡金属及其氧化物和制备负载化的固体酸催化剂。综述了介孔分子筛经功能化制备及催化性能的研究进展。     

新型有序介孔炭基固体酸的制备及其催化双酚A合成

采用软模板法制得具有高度有序介孔孔道结构、高密度-SO₃H基团的新型有序介孔炭基固体酸催化剂。通过N₂吸附-脱附、X射线衍射、透射电镜、EDX能谱以及酸碱滴定等手段对催化剂进行了表征,考察了炭化温度对介孔炭基固体酸催化剂介孔孔道结构、表面酸性以及催化活性的影响。结果表明,500 ℃是最适宜的炭化温度,该炭化温度下制备的催化剂介观有序性较好且酸密度较高。所得的催化剂在丙酮与苯酚缩合生成双酚A的反应中表现出明显高于其它3种固体酸催化剂（001×7,D072,无定型炭基固体磺酸）的活性。可见,有序介孔炭基固体酸是一种高效的新型固体酸催化剂,在双酚A领域具有较好的应用潜力。     

磺酸基功能化的双金属掺杂介孔材料HSO_3-Zr-La-SBA-15催化酯水解反应的应用

以3-巯丙基-三甲氧基硅烷为有机功能试剂,采用后接枝法,合成了磺酸基功能化的介孔材料HSO3-ZLS。制备的磺酸基功能化介孔材料对羧酸酯水解的催化性能研究表明,功能化的新型介孔材料催化活性高,是环境友好型催化剂。     

磺酸型固体酸催化剂的制备与应用研究进展

将磺酸基团引入到固体载体表面制备磺酸型固体酸以替代传统的硫酸催化剂．对磺酸型固体酸催化剂的制备和应用研究进展进行了综述．介绍了在中孔硅分子筛（如MCM-41、SBA-15）、中孔炭分子筛（如CMK-3、CMK-5）、半炭化炭材料、炭纳米管等载体上引入磺酸基团的方法和其中一些催化剂的催化性能,探讨这些制备方法和所制得催化材料的优点和存在的问题．     

绿豆碳基固体酸催化剂的制备及其活性研究

以绿豆为原料,采用碳化-磺化法制备了一种新型碳基固体酸催化剂,对其理化特性进行了表征,并考察了其催化油酸甲酯化活性。研究表明,催化剂中硫元素含量为8.671%,傅里叶红外转换光谱验证了磺酸基功能团的存在。研究表明,较适宜的碳化时间为15 min,碳化温度为350℃,磺酸化时间为1 h,磺酸化温度为80℃。催化剂重复利用5次后及催化活性再生后再重复利用5次,催化转化率依然维持在68%左右。微波可以辅助催化油酸甲酯化反应的进行,微波功率为400 W,温度为65℃时,油酸甲酯化的转化率高达87%左右。总体而言,研究中自制绿豆碳基固体酸催化剂是一种性能稳定、绿色环保的固体酸催化剂,可在微波辅助固体酸法制备生物柴油的工业化生产中推广应用。     

绿豆碳基固体酸催化剂的制备及其活性研究

以绿豆为原料,采用碳化-磺化法制备了一种新型碳基固体酸催化剂,对其理化特性进行了表征,并考察了其催化油酸甲酯化活性。研究表明,催化剂中硫元素含量为8.671%,傅里叶红外转换光谱验证了磺酸基功能团的存在。研究表明,较适宜的碳化时间为15 min,碳化温度为350℃,磺酸化时间为1 h,磺酸化温度为80℃。催化剂重复利用5次后及催化活性再生后再重复利用5次,催化转化率依然维持在68%左右。微波可以辅助催化油酸甲酯化反应的进行,微波功率为400 W,温度为65℃时,油酸甲酯化的转化率高达87%左右。总体而言,研究中自制绿豆碳基固体酸催化剂是一种性能稳定、绿色环保的固体酸催化剂,可在微波辅助固体酸法制备生物柴油的工业化生产中推广应用。     

合成双酚A催化剂研究新进展

介绍了用于合成双酚A催化剂离子交换树脂的改性、固体酸催化剂,包括分子筛、杂多酸、自主合成固体酸以及离子液体等新型催化剂;分析比较了它们的催化效果;评述了介孔分子筛、杂多酸、离子液体等催化剂的催化性能和存在的问题,并对未来催化剂的发展提出了建议。     

碳基固体酸催化Micheal加成反应的研究

碳基固体酸催化剂以其优良的催化活性和较强的选择性等优点,被广泛地应用到催化化学的各个领域,成为当前热点催化剂之一。通过水热碳化呋喃甲醛与羟乙基磺酸,合成了一类新型碳基固体酸材料,并以其为催化剂,进行Micheal加成反应。     

介孔分子筛SBA-15在催化领域的应用进展

从负载固体酸催化剂、金属和金属氧化物以及手性催化剂三方面综述了介孔分子筛SBA-15在催化领域应用的研究进展;并展望了介孔分子筛SBA-15在催化领域的研究方向。     

Ordered Mesoporous Materials with Improved Stability and Catalytic Activity

Microporous crystals of zeolites such as Y, Beta, and ZSM-5 are widely used commercial catalysts, but their applications are strongly limited by their small pore sizes. Recent progress in solving this is used to ordered mesoporous materials such as MCM-41, HMS, and SBA-15. These mesoporous materials have pore diameters of 2.0–30 nm and exhibit good catalytic properties for the catalytic conversion of bulky reactants. However, when compared with microporous crystals of zeolites, the catalytic activity and hydrothermal stability are relatively low, which severely hinders their practical applications in industrial catalytic reactions such as petroleum cracking. The relatively low catalytic activity and hydrothermal stability can be attributed to the amorphous nature of the mesoporous walls. In this account, we systemically review the routes for improving catalytic activity and hydrothermal stability of mesoporous materials, which include (1) acidic sulfated zirconia supported in mesoporous materials; (2) strongly acidic and thermally stable mesostructured sulfated zirconia with tetragonal crystalline phase; (3) strongly acidic and hydrothermally stable mesoporous aluminosilicates synthesized in alkaline media; (4) strongly acidic and hydrothermally stable mesoporous aluminosilicates synthesized in strongly acidic media; (5) hydrothermally stable mesoporous titanosilicates with catalytically active titanium species in oxidations; (6) high-temperature generalized synthesis of ultrastable ordered mesoporous silica-based materials by using fluorocarbonhydrocarbon surfactant mixtures.     

Highly Effective Oxidative Dehydrogenation of Propane Over Vanadia Supported on Mesoporous SBA-15 Silica

Vanadia-containing mesoporous SBA-15 catalysts were prepared and characterized for the oxidative dehydrogenation (ODH) of propane. It is demonstrated that the vanadia-supported SBA-15 catalysts exhibit a much higher catalytic activity than those reported in the literature obtained over vanadium-supported mesoporous MCM-41 catalysts in the ODH of propane. The high catalytic performance of the mesoporous SBA-15 catalysts is attributed to the particularly large pore diameters and low surface acidity.     

Preparation of surface-silylated and benzene-bridged Ti-containing mesoporous silica for cyclohexene epoxidation

Organic–inorganic hybrid Ti-containing mesostructured materials were directly synthesized from tetrabutyl titanate in acidic media by using a non-ionic surfactant P123 as a structure-directing agent, tetraethoxysilane as an inorganic silicon source and 1,4-bis-(triethoxysilyl)benzene as organicsilica. The benzene-bridged Ti-containing periodic mesoporous organosilica Ti-SBA-15-ben was further modified by surface silylation with trimethylchlorosilane. The products were characterized by various means. We find the materials maintained good mesoporous structure, their hydrophobic properties were significantly improved after silanization, and the organic silicon source in the pore walls was favorable for obtaining tetravalent active titanium ions. The catalysts were evaluated in cyclohexene epoxidation with tertbutyl hydroperoxide as an oxidant agent. With Ti-SBA-15-ben as the catalyst, the epoxide selectivity and cyclohexene conversion were improved to 59.9 and 34.7 % respectively. Moreover, surface hydrophobization by silylation treatments further increased the epoxide selectivity to 71.5 %.     

Templated mesoporous carbons for supercapacitor application

Mesoporous carbons prepared by an inverse replica technique have been used as electrodes for electrochemical capacitors. Such well-sized carbons were prepared from mesostructured SBA-16 silica materials that served as templates whereas polyfurfuryl alcohol was the carbon precursor. Two highly mesoporous carbons characterized by 3 and 8 nm average pore diameter were tested in various electrolytic solutions (acidic, alkaline and aprotic).It can be concluded that templated mesoporous carbons with tailored pore size distribution are very promising materials to be used as electrodes in supercapacitors. The design of their pore size allows suiting the dimensions of electrolyte ions and efficient charging of the electrical double layer is achieved especially at high current load. Definitively better capacitance performance has been found for carbon with 3 nm pores range, however, cycling performance depends not only on the pore size.     

炭催化甲烷裂解制氢研究进展

综述了炭催化甲烷裂解制氢的研究进展,重点阐述了具有不同孔结构特征的微孔炭、介孔炭和金属负载型炭催化剂在甲烷催化裂解制氢过程中的催化性能和影响规律。与微孔炭具有较高初始活性、较低稳定性相比,介孔炭或具有微孔/介孔结构的多级孔结构炭材料表现出更高的催化活性和寿命;将金属负载于炭材料制得的金属负载型催化剂可同时利用金属的高活性和炭材料相对较高的稳定性提高催化裂解甲烷性能。该文还对炭催化甲烷裂解机理进行概述,指出通过调控炭材料结构与组成、提高甲烷催化裂解性能和加强对炭催化甲烷裂解机理研究是今后发展的方向。     

Preparation of sulfated alumina supported on mesoporous MCM-41 silica and its application in esterification

New types of mesoporous SA/MCM-41 solid acid catalysts were prepared by loading sulfated alumina (SA) on MCM-41. The prepared catalysts were characterized by XRD, IR, N₂ physisorption, elemental analysis, FT-IR of adsorbed pyridine and NH₃-TPD. The esterification of acetic acid with n-butanol and citric acid with n-butanol were used as model reactions to test the catalytic activities and reusability of the SA/MCM-41 solid acid catalysts. Compared with SA catalyst, SA/MCM-41 catalysts exhibited higher catalytic performances, which were attributed to their high BET surface area and large pore volume. Moreover, 20SA/MCM-41 solid acid catalyst showed excellent reusability in both esterifications.     

Sulfonated ordered mesoporous carbon for catalytic preparation of biodiesel

Sulfonated ordered mesoporous carbons (OMC) have been synthesized by covalent attachment of sulfonic acid-containing aryl radicals on the surface of mesoporous carbons. Compared with other solid acid catalysts, the resulting materials show stable and highly efficient catalytic performance in biodiesel production with the highest conversion reaching 73.59%. The reported carbon-based catalysts can be reused for several times without loss of activity. Furthermore, sulfonated OMC with larger pore size makes active sites easily accessible and exhibits higher catalytic ability.     

A mesoporous Pt-SBA-15 nano architecture with catalytic functions on oxidation of CO

Among many kinds of noble metal catalysts, platinum is the most efficient and widely used as automotive exhaust catalysts for treatment to remove poison gases. Due to the regular pore system and controllable pore size, mesoporous silica has been acknowledged as supports of adsorption, separation, catalysts for the extremely large surface areas and shape selective properties. SBA-15 supported Pt particles are prepared by a facile method and characterized by X-ray diffraction, Transmission Electron Microscopy and N₂ isotherms techniques. Results indicate that the Pt precursor is introduced into the mesoporous successfully and all of the particles are confined in SBA-15 with monodispersed form and uniform size. The catalytic activity of Pt-SBA-15 on oxidation of carbon monoxide are also investigated and the result indicate that the catalysts possess high catalytic activity, catalytic efficiency and stability on oxidation of CO.     

Competent,selective and high yield of 7-hydroxy-4-methyl coumarin over sulfonated mesoporous silica as solid acid catalysts

Highly ordered mesoporous MCM-41 and SBA-15 have been synthesized and functionalized with different amounts of propyl sulfonic acid groups using 3-mercaptopropyltrimethoxysilane as sulfur source. The synthesized catalysts have been well-characterized by different techniques such as XRD, FTIR and BET surface area and pore size distribution by BJH method. FTIR spectra of chemisorbed pyridine and temperature programmed desorption of NH₃ techniques have been successfully used to characterize the acidic sites. The results showed that, both surface area, mean pore diameter and pore volume decrease as the extent of sulfonation increase. XRD results and TEM images confirm the stability of mesoporous long range order even after sulfonation process done. In addition, the study also showed that, sulfonation enhances the surface acidity and new moderate and strong acid sites were created. All the sulfonated catalysts under investigations have been found to be highly active and selective for the Pechmann condensation reaction of resorcinol with ethyl acetoacetate. More than 98% yield of 7-hydroxy-4-methyl coumarin was obtained with 100% selectivity. Presence of high number of moderate and strong Brönsted acid sites in sulfonated catalysts help in achieving high yields. Furthermore, the MCM-41 sulfonated catalysts showed higher catalytic performance due to their higher surface acidities.     

The effect of mass transfer on the catalytic combustion of benzene and methane over palladium catalysts supported on porous materials

Catalytic combustion of benzene and methane over palladium catalysts supported on FAU and MOR zeolites and MCM-41 and KIT-1 mesoporous materials were studied to illustrate the effect of pore size and shape of supports on their catalytic activities. The palladium catalysts supported on mesoporous materials showed high activity and a steep increase in the conversion of benzene with rising temperature. The low activity of palladium catalysts supported on FAU zeolite was ascribed to mass transfer limitation. However, conversion profiles of methane on palladium catalysts were similar, although their supports were different as zeolites and mesoporous materials. The catalytic behavior of palladium catalysts in the combustion of benzene and methane was explained by the diffusion properties of fuels in the pores of zeolites and mesoporous materials.