【作者】 冯英子；

【导师】 李忠；

【作者基本信息】 华南理工大学 ， 能源材料工程， 2010， 硕士

【摘要】 天然气(甲烷)绿色环保,经济安全,被认为是一种较理想的汽车燃料。然而车载存储问题限制了天然气的应用。在当前技术中,吸附技术是最为经济有效和最具发展前景的存储方式之一。吸附剂是吸附技术的核心和关键。金属-有机骨架材料(MOFs)由于具有巨大比表面积,孔径可调、表面化学性质可修饰,是近年来发展迅速的一类多孔材料,在能源环境领域具有广阔的应用前景。本文针对能源气体中天然气的存储,选择合成具有高比表面积的MOF-5和MIL-101材料,主要考察了MOF-5、ZIF-8、MIL-101和HKUST-1等几种MOFs材料对甲烷的吸附性能,具有研究意义和应用前景。本文研究了MOF-5晶体合成的反应条件对MOF-5晶体的表面形貌、晶体结构和孔隙结构等物理化学性能的影响。利用SEM、XRD和快速比表面积和孔径分布分析仪对所制备的MOF-5晶体进行表征分析。研究结果表明:以二乙基甲酰胺为溶剂,将Zn2+/对苯二酸摩尔配比为2.64的合成液中置于130°C下反应4小时可得到小颗粒(40-70μm)和高比表面积( S Langmuir=2595m2/g)的MOF-5晶体。本文研究了CH4在MOF-5、ZIF-8、ZIF-62、MIL-101、HKUST-1晶体颗粒上的吸附相平衡。采用重量法测定了CH4吸附等温线,估算出CH4气体在MOF-5、MIL-101、HKUST-1上的等量吸附热。结果表明:Langmuir等温线方程可以准确地描述CH4在MOF-5、MIL-101、HKUST-1上的吸附数据;在299.15K和40bar条件下,CH4在HKUST-1上的吸附量最大(93.8mg/g);CH4在MOF-5、MIL-101、HKUST-1上等量吸附热分别为10.85～8.14kJ / mol,15.75～13.23kJ/mol,18.02～9.03kJ / mol。本文研究了ZIF-62和SBA-15吸附苯的性能。结果发现:在p / po≤0.4时,ZIF-62多孔材料相对于介孔分子筛SBA-15对苯具有更大的吸附能力。苯在ZIF-62上的吸附等温线为典型的Ⅰ型吸附等温线,298K时,ZIF-62对苯的平衡吸附量达到185mg/g,苯在ZIF-62上的吸附遵循拟一级动力学方程。更多还原

【Abstract】 Natural gas (methane) is considered as an ideal vehicle fuel due to its environmental protective, economy and safe. However, the application of natural gas in Vehicle has been limited by the difficulties in on-board storage. Adsorption nature gas is considered a most prospective storage method. And the key of adsorption nature gas is to develop efficient adsorbents. A new type of porous materials, metal-organic frameworks, is believed to be a kind of very potential nature gas adsorbent, which has large surface area, designable pore texture and several advantages. This dissertation is mainly concerned with study on methane adsorption onto several novel metal-organic frameworks, MOF-5, ZIF-8, ZIF-62, MIL-101and HKUST-1. This research mainly involves synthesis and characterization of the MOF-5 crystals, determination of CH4 adsorption thermodynamics on the MOF-5, ZIF-8, ZIF-62, MIL-101and HKUST-1 particles. This study tries to answer the questions of engineering application and adsorpion science, like the uptake of CH4 at different temperature or under different pressure and so on, which has scientific research value and practical significance.The effects of synthesis condition on physical properties of MOF-5 crystals, including the morphology, crystal structure and porous texture were investigated. SEM, XRD and N2 adsorption/desorption were used to characterize the morphology, crystal structure and porous texture properties of MOF-5 crystals. Results showed that MOF-5 crystals whose partical sizes ranged from 40 to 70μm and surface area was up to 2595m2/g were obtained under the following conditions: synthesis temperature of 130°C, reaction time of 4 hours, the Zn2+/BDC molar ratio of 2.64 and N, N-diethylformamide as the solvent.Adsorption equilibriums of CH4 on the MOF-5, ZIF-62, MIL-101 and HKUST-1 particles were studied by using gravimetric method. The isosteric adsorption heat of CH4 on the MOF-5, MIL-101 and HKUST-1 were estimated. Results showed that CH4 adsorption behavior can be accurately described by Langmuir isotherm equation; HKUST-1 had the largest amount of CH4 adsorbed compared to the other MOFs crystals investigated in this work. The amount adsorbed of CH4 on the HKUST-1 was up to 93.8mg/g at 299.15K and 40bar. The isosteric adsorption heats of CH4 on the MOF-5, MIL-101 and HKUST-1 particles were in the range of 10.85-8.14kJ/mol, 15.75-13.23kJ/mol and 18.02-9.03kJ/mol, respectively.Methane adsorption properties onto ZIF-62 and SBA-15 were studied in this research. Results showed that the amount adsorbed of benzene on the ZIF-62 was more than that on the SBA-15 if p / po≤0.4. Asorption isotherm of benzene on ZIF-62 was typical type-I adsorption isotherm. The equilibrium amount adsorbed of benzene on the ZIF-62 was up to 185mg/g. And sorption of benzene on ZIF-62 conforms to pseudo-first-order equation.更多还原