【作者】 伍刚；

【导师】 王金渠；

【作者基本信息】 大连理工大学 ， 化学工艺， 2005， 硕士

【摘要】 石油价格的频繁波动及人们环境保护意识的提高促进了车用燃料替代产品的开发。目前,较有前景的替代燃料是天然气。天然气主要由甲烷(85%)、少量的乙烷和其他碳氢化物、氮气和二氧化碳所组成。作为一种良好的吸附剂,活性炭被广泛应用于天然气的吸附存储。研究表明,作为天然气吸附剂的理想活性炭孔径应在2. 0nm左右。尽管许多学者在孔径和孔分布控制方面做了大量的研究工作,然而,炭结构的复杂性还是使得传统活化方法难以用来制备孔径严格受控的多孔炭材料。MCM-48、 NaY分子筛捌有规则的孔道结构和精细的纳米空间,可以作为无机模板应用到多孔炭材料的合成制备中。在本文的研究中,使用非离子表面活性剂聚乙二醇辛基苯基醚(OP-10) 和阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)混合模板剂法在低模板剂质量分数(5. 6%),低表面活性剂/硅条件(摩尔比0. 174:1) 下水热法合成出了立方相的MCM-48介孔分子筛。同时,以硅溶胶为硅源,硫酸铝为铝源,氢氧化钠作碱源和去离子水,采用水热合成法合成了NaY沸石分子筛。采用NaY沸石分子筛作模板,乙酰丙酮为有机前驱体,使用液相浸渍-气相沉积工艺合成了富含微孔和中孔结构的多孔炭材料并对其进行了表征。所合成的多孔炭比表面积1351 m2/g,孔容0. 892 cm3/g,微孔率0. 63,孔径分布多在1. 0nm～3. 0nm之间。也使用了其他的有机前驱体合成了沸石模板孔炭,并比较了几种沸石模板炭的结构特征。纯硅分子筛缺乏酸性活性位,以MCM-48介孔分子筛作模板时,加入柠檬酸和糠醇作为有机前驱体,在未对MCM-48介孔分子筛进行改性的条件下,合成了具有一定有序孔道结构的模板中孔炭。该模板中孔炭的XRD衍射在2 θ=2. 8°左右显示了一强度较高的衍射峰。BET比表面积1072m2/g,最可几孔径3. 0nm,孔容0. 82cm3/g。更多还原

【Abstract】 Instability in the oil markets and increase in environmental concerns have stimulated research for alternative transportation fuels. One alternative to gasoline is natural gas, which consists primarily of methane (85-95%) with minor amounts of ethane, other higher-order hydrocarbons, nitrogen, and carbon dioxide.Activated carbons (AC) are studied as the storage of natural gas by adsorption forms. It shows by research that the ideal AC should have an average micropore width of 2.0 run for the adsorption natural gas system. However, the complexity of the carbon structure prevents the conventional activation processes from preparing carbon materials with strictly controlled pore structure, although voluminous research has been done and great effort has been made toward the control of pore size and its distribution. To meet such a requirement, many novel approaches to control pore structure have been developed. Melocular sieves, such as MCM-48 and NaY, are characterized by their regular channel structure and are utilized for synthesizing unique carbon materials.In this work, mesoporous molecular sieve MCM-48 by hydrothermal method using nonionic surfactant p-Octyl polyethylene glycol phenyl ether and cationic surfactant cetyltrimethyl-ammonium bromide (CTAB) as co-template were synthesized. The synthesis was conducted at a very low mass fraction mixed surfactants (about 5.6%) and a very low molar ratio of total surfactants to silica (about 0.174:1). At the same time, zeolite NaY was synthesized by hydrothermal method using silica sol, aluminium sulfate, sodium hydroxide and deioned water.Porous carbon with controlled pore size distributions between 1.0nm and 3.0nm were synthesized using zeolite NaY as a template. Acetylacetone was employed as a carbon precursor to prepare porous carbons by impregnation method and CVD method. The porous carbon prepared exhibited two kind of pore structure: microporus and mesoporous, with surface area, microporisity and micropore volume of 1351m2/g, 0.63 and 0.892cm3/g respectively. Other carbon precursors are used such as citric acid, furfuryl alcohol and phenolic resin.Mesoporous carbon was fabricated using molecular sieve of MCM-48 as template, which is lower ordered in pore structure, which shows a peak at 2 θ =2.8°. Citric acid and furfurylalcohol were employed as carbon precursor to prepare mesoporous carbons with surface area of 1072 m2/g and 0.87cm3/g respectively. Citric acid also improved the acidity of molecular sieves when mesoporous carbons are synthesized.更多还原