介孔分子筛MCM-41在废水处理中的应用

介孔分子筛MCM-41具有高度有序排列的孔道结构、孔径均匀且尺寸可调、高比表面积、较大的孔体积及吸附容量,孔道表面具有易于修饰的硅羟基,在废水处理中吸附重金属离子、有机污染物等方面具有很大的应用价值。对近几年介孔分子筛MCM-41用于处理废水中污染物的应用情况进行了综述。     

介孔分子筛在挥发性有机化合物吸附中的研究进展

挥发性有机化合物(VOCs)是破坏生态环境质量的重要污染物,近年来发现介孔分子筛对VOCs有较好的吸附效果.综述了近年来介孔分子筛在VOCs吸附中的研究进展,详细讨论了VOCs在介孔分子筛吸附剂上的吸附过程,并对以后介孔分子筛吸附剂的研究提出了建议.     

介孔分子筛改性及在吸附脱硫中的应用

介孔分子筛由于具有较大的比表面积、孔容、孔径等优点使得其在吸附分离等领域得到了广泛的应用。本文综述了介孔分子筛改性的不同方法,包括嵌入法、负载法,以及有机-无机杂化介孔材料的制备等。对介孔分子筛在吸附脱硫方面的最新研究进展进行了总结,包括对燃料油、天然气、煤气中硫化物的吸附脱除,以及H2S、SO2等大气污染物的吸附脱除。同时对介孔分子筛的改性及发展前景进行了展望,合成新型有机-无机杂化介孔材料并将其应用于吸附等领域是未来发展的主要趋势。     

有序介孔材料SBA-15吸附分离污水中铬离子的研究

重金属是水体中重要污染物之一,对人体的危害极大,考虑以有序介孔材料SBA-15脱除废水中铬离子。实验研究了吸附剂粒度、吸附温度、铬离子浓度、酸度、吸附时间和吸附剂用量等对脱除铬离子的影响。结果表明：低温、低铬离子浓度、低酸度、长吸附时间和高吸附剂用量有利于有序介孔材料SBA-15对铬的去除,铬去除率可达99％以上。沸石分子筛脱除废水中铬离子效果好、工艺简单、吸附剂可循环使用,具有一定的应用前景。     

多元素介孔分子筛在净化含Pb(Ⅱ)废水中的应用研究

以钾长石为主要原料,十六烷基三甲基溴化铵为模板剂在碱性条件下水热合成了多元素介孔分子筛.分别采用X射线粉晶衍射和氮气吸附-脱附等温线对所合成样品的结构性能进行了表征.利用介孔分子筛高比表面积和较大孔径的特点,将其用于含有重金属离子废水的净化处理,并研究了所合成样品对废水中Pb(Ⅱ) 的吸附规律,对吸附剂用量、吸附时间、溶液pH值、温度和初始浓度等因素进行了详细的实验研究.     

有序介孔碳吸附剂的研究进展

介绍了有序介孔碳吸附剂在吸附中的重要作用,总结了有序介孔碳应用于处理染料废水,去除水中芳香有机污染物,去除重金属离子以及吸附生物分子中的研究现状.展望了有序介孔碳应用于吸附的发展前景.     

KIT-6介孔分子筛的研究进展

介孔材料由于其孔道规整有序、孔径大小可调,可以实现微孔分子筛难以完成的大分子的吸附、分离反应,近年来介孔分子筛合成和应用的研究引起了学者们的广泛关注.KIT-6介孔分子筛具有高比表面积,三维连通的双螺旋孔道结构的优点,十分适合应用于催化、吸附和药物领域.概述了 KIT-6介孔材料的合成和不同应用领域的研究进展.     

功能化介孔材料吸附性能与机理的研究进展

综述了功能化介孔材料的孔径结构、改性基团和吸附条件对废水中的有机污染物、染料分子和重金属离子以及生物大分子、药物分子、CO2和挥发性有机气体污染物的吸附脱除效果的影响,还介绍了功能化介孔材料对液晶材料中的微量无机离子和大极性有机杂质的吸附脱除效果,指出了新型功能化介孔材料的开发和吸附环境的研究是未来的研究热点和发展趋势。     

碱处理微孔分子筛制备介-微复合分子筛应用研究进展

介孔-微孔复合结构分子筛表现的优良的协同作用和催化吸附性能得到了越来越多科研工作者们的广泛重视。重点综述了利用NaOH碱液处理不同微孔分子筛合成介孔-微孔复合分子筛材料的应用研究进展,分析比较了制备过程中不同因素对于介孔和微孔形成的影响。展望了这种利用碱液处理一元孔结构得到两元复合分子筛在催化和吸附方面的发展前景。     

电子显微镜研究分子筛的新进展

电子显微镜在沸石分子筛的研究中起着重要的作用.阐述了透射电子显微镜(TEM)和扫描电子显微镜(SEM)技术研究沸石分子筛的原理,描述了使用不同种类的电子显微镜剖析沸石分子筛的形态、尺寸、粒径分布等,并介绍了近年来电镜技术对沸石分子筛,特别是对新型功能介孔材料及手性介孔材料的研究进展.电子显微镜的发展将推动分子筛及纳米材料在选择性催化/吸附过程中的应用.     

介孔SBA-15的孔径尺寸对小牛血清蛋白和溶菌酶蛋白吸附的影响(英文)

In this paper,the effects of pore-size of SBA-15 on the adsorption kinetics and equilibrium of large protein molecules Bovine serum albumin(BSA)and lysozyme(LYS)have been investigated.The mesoporous molecular sieve SBA-15 with six different pore sizes were synthesized with P123 triblock copolymer as the template agent,and 1,3,5-trimethylbenzene(TMB)and isopropyl alcohol as the pore-expanding agent.The samples were characterized by N2 adsorption/desorption,Scanning Electron Microscopy(SEM),Transmission Electron Microscopy(TEM)and X-Ray Diffraction(XRD).It is found that BSA and LYS were adsorbed rapidly on SBA-15 materials with large pores.The BSA adsorption capacity of sieve with the pore diameter of 21.4 nm reached 500 mg·g-1 within 25 minutes.However,if the pore diameter was smaller than 14 nm,the BSA adsorption capacity of the sieve was only about 220 mg·g-1.The adsorption equilibrium data fits in the Langmuir model,where the coefficient of effective use of specific area of mesoporous molecular sieve was found to be 0.03,0.18,0.37 and 0.48,corresponding to the pore diameter of 10.1 nm,13.2 nm,15.4 nm and 21.4 nm,respectively.The equilibrium loading amount of LYS on SBA-15 materials with pore size of 15.4 nm could be up to 1000 mg·g-1.The coefficient of effective use of surface area of mesoporous molecular sieve with diameter of 3.9 nm,7.4 nm,10.1 nm,13.2 nm and 15.4 nm was 0.10,0.47,0.56,0.71 and 0.79,respectively.It is also noted that greater pore size of mesoporous molecular sieve would lead to a higher coefficient of effective use of surface area.     

微波条件下钴掺杂对MCM-41分子筛结构性能的影响

以十六烷基三甲基溴化铵为模板剂,通过微波辐射方法合成钴掺杂MCM-41介孔分子筛。采用X射线粉末衍射、红外光谱、透射电子显微镜、等离子发射光谱和N2吸附-脱附等技术对样品进行表征。结果表明：样品经550℃焙烧后,模板剂被有效去除。微波辐射条件下,成功合成出钴掺杂介孔分子筛样品。与纯硅的分子筛样品相比,钴掺杂的介孔分子筛比表面积增大,孔径分布均匀。     

MCM-41介孔分子筛吸附性能的热力学和动力学分析

实验以亚甲基蓝作为模型吸附质,探讨了MCM-41介孔分子筛对模型吸附质亚甲基蓝的吸附性能,并对其吸附过程进行了热力学和动力学分析。结果表明,MCM-41介孔分子筛的吸附率高达94%,对亚甲基兰的吸附符合二级吸附动力学,MCM-41对亚甲基兰的吸附行为属于Freundlich等温吸附,整个吸附过程属于放热反应。     

组合处理工艺下硅藻土微观组织演变及孔隙结构变化

将硅藻土制成硅藻土/分子筛复合材料,其比表面积和吸附能力将显著提高。本文利用水洗-烧结-酸性水热系列组合处理工艺制备硅藻土/磷酸铝分子筛复合材料,同时验证外加铝源形成磷酸铝分子筛的可行性,探讨高品质硅藻土形成时的微观组织演变行为及孔隙结构变化规律。结果表明:硅藻土的孔隙结构包括大孔、介孔和少量的微孔结构,水洗处理仅有物理提纯作用;500 ℃烧结可以疏通硅藻土壳体的孔洞,但烧结温度过高会导致管状结构的坍塌;酸性水热处理能够合成具有介孔结构的磷酸铝分子筛,而且随着外加铝源的加入,硅藻土/分子筛复合材料中磷酸铝分子筛含量增加,当外加铝源为硅藻土中铝含量的1.5倍时,其比表面积和吸附性能达到最大。     

粉煤灰合成中孔分子筛MCM-41及其吸附性能

以粉煤灰为初始原料,十六烷基三甲基溴化铵（CTAB）为模板剂采用水热法合成出中孔分子筛MCM-41,采用小角XRD、TEM、氮气吸附-脱附等对样品的物相、比表面积、孔径、孔体积等进行表征,并研究了样品分子筛对镍离子的吸附性能。结果表明：样品具有典型中孔分子筛MCM-41的特性,比表面积为576 m^2/g,平均孔径为5.53 nm;Ni^2＋能定量吸附在样品分子筛上,最大去除率可达到96%,吸附性能符合Langmuir吸附方程特征,并且随吸附液pH的增大,Ni^2＋去除率也随之增加。     

含Ni介孔分子筛的合成及其对苯加氢催化性能

采用水热法合成出不含镍和含镍的硅基介孔分子筛.利用XRD、FT-IR、TPR、TEM和比表面孔径测定等手段对样品进行了表征.结果表明：合成出有序性好的介孔分子筛（MCM-41）,550 ℃焙烧可以将模板剂有效去除,所合成介孔分子筛负载Pt后介孔有序性降低,但是介孔结构仍然存在.苯催化加氢反应研究表明：不含Ni的介孔分子筛不具有加氢活性,当将其负载Pt后具有苯加氢催化活性;含Ni介孔分子筛本身具有苯加氢活性,含Ni介孔分子筛负载Pt后苯加氢催化活性有较大的提高,所有样品的环己烷选择性都接近100 %,说明含Ni介孔分子筛可以直接作为苯加氢反应的催化剂或作为苯加氢催化剂良好的载体.     

分离乙稀-乙烷的Cu-MCM-48介阵络合吸附剂的合成、表征及吸附平衡研究

Copper incorporated MCM-48 molecular sieve adsorbents with different Cu content have been hydrothermally synthesized.The samples have been characterized by vmous physicochemical methods,including X-ray difrraction(XRD),nitrogen adsorption(N2)and X-ray photoelectron spectroscopy(XPS).The results reveal that Cu-MCM.48 with mass fraction of copper up to 10?n still retain the uniform mesoporous framework of MCM-48.The copper in the framework of MCM-48 was easily auto-reduced to Cu(Ⅰ)in N2 at high temperature,which did not alter the mesoporous structure of MCM-48.The adsorption equilibrium isotherlnS of ethylene and ethane on these molecular sieve adsorbents have been measured at 30℃.At 100 kPa,the adsorption capacities of ethylene on 5Cu-MCM一48 and 10Cu-MCM-48 are higher than those on MCM-48.The 10Cu-MCM-48 molecular sieve adsorbent has a higher selective adsorption ratio of ethylene to ethane,the separation factor is 3.8,and the amount ofethylene adsorbed is 11.1 ml·g-1.     

分离乙烯-乙烷的Cu-MCM-48介孔络合吸附剂的合成、表征及吸附平衡研究

Copper incorporated MCM-48 molecular sieve adsorbents with different Cu content have been hydrothermally synthesized. The samples have been characterized by various physicochemical methods, including X-ray diffraction （XRD）, nitrogen adsorption （N2） and X-ray photoelectron spectroscopy （XPS）. The results reveal that Cu-MCM-48 with mass fraction of copper up to 10 % can still retain the uniform mesoporous framework of MCM-48. The copper in the framework of MCM-48 was easily auto-reduced to Cu（I） in N2 at high temperature, which did not alter the mesoporous structure of MCM-48. The adsorption equilibrium isotherms of ethylene and ethane on these molecular sieve adsorbents have been measured at 30℃. At 100 kPa, the adsorption capacities of ethylene on 5Cu-MCM-48 and 10Cu-MCM-48 are higher than those on MCM-48. The 10Cu-MCM-48 molecular sieve adsorbent has a higher selective adsorption ratio of ethylene to ethane, the separation factor is 3.8, and the amount of ethylene adsorbed is 11.1 ml·g ^-1.     

Photodegradation of aromatic pollutants in water over TiO2 supported on molecular sieves

TiO₂ was supported on porous materials, including NaY and Na-mordenite zeolites, as well as mesoporous MCM-41 molecular sieve by using impregnation method with organic solvents. The products were characterized with powder XRD, BET surface area measurement, TEM, IR, Raman and UV–VIS spectroscopies. The supported TiO₂ was crystallized in anatase structure and the intensity of its X-ray diffraction peaks increased with TiO₂ loading. In contrast, the total surface area of the supported catalyst decreased with TiO₂ loading. A blue shift of the absorption edge in the UV–VIS spectra was observed when TiO₂ particle size decreased, a phenomenon corresponding to the particle size quantization effect. For photodegradation of aromatic pollutants in water, the activity was found strongly influenced by the chemical nature of the pollutant and the surface property of the support. For volatile pollutants such as benzene and chlorobenzenes, molecular sieve supports facilitated the photodegradation reaction by providing high surface area for adsorption. Moreover, there is an optimal loading of TiO₂ to achieve the best photocatalytic activity on various supports. The supports in contrast did not show positive contribution in degradation of hydrophilic pollutants such as phenol.     

H-Al-MCM-48介孔分子筛的合成及其催化性能研究

采用水热法合成出n（Si）/n（Al）=25的Al-MCM-48介孔分子筛,并用NH4NO3溶液处理得到H型的H-Al-MCM-48介孔分子筛。采用XRD、N2吸附–脱附、TEM等手段对样品进行了表征,并研究了样品对苯酚与叔丁醇烷基化反应催化性能。结果表明,合成的Al-MCM-48样品具有高度有序的立方介孔结构,H-Al-MCM-48的介孔有序性和比表面积有所降低,但样品仍具有MCM-48的立方结构。H-Al-MCM-48在苯酚与叔丁醇的烷基化反应中显示出良好的催化活性,在反应温度为140℃时苯酚的转化率高达98.9%。