【作者】 黄思思；

【导师】 李忠；

【作者基本信息】 华南理工大学 ， 环境工程， 2010， 硕士

【摘要】 VOCs污染已成为环境污染的主要源头之一,它极大地破坏着生态环境,严重地威胁人类健康和影响社会的可持续发展,有效地治理VOCs的环境污染已迫在眉睫。吸附技术被认为是一种极具发展潜力的VOCs治理技术,新型的多孔吸附材料是吸附技术的核心,研制对VOCs具有高效吸附性能的新型多孔材料成为技术的关键。本文主要探索合成MOF-5和MIL-101材料并测定其吸附VOCs的性能,论文工作主要涉及MOF-5和MIL-101材料的合成及表面性质的表征,测定苯和甲苯在MOF-5和MIL-101材料上的吸附等温线和吸附动力学曲线,估算甲苯在MIL-101材料上的吸附/脱附活化能,属于环境工程、化学工程和材料工程领域,具有重要的研究意义和实际应用背景。本文研究了合成条件对MOF-5晶体比表面积和孔隙结构等性能的影响。研究结果表明:以DMF为溶剂,将Zn2+/H2BDC摩尔比为3的合成液中置于130℃下油浴反应4小时后经过一定的纯化和活化处理,可成功得到小颗粒(20-60μm)、较高比表面积(SLangmuir =1022m2/g)和较大孔容(0.45 cm/g)的MOF-5晶体。本文研究了合成条件对MIL-101晶体比表面积和孔隙结构等性能的影响。研究结果表明:Cr3+、对苯二甲酸、氢氟酸和水以一定配比在210℃微波辐射反应1小时,并经过一定的纯化和活化处理,可得到高质量、高纯度的纳米级(40-90 nm)微小颗粒、大比表面积(SLangmuir =4443m2/g)和大孔容(1.89 cm3/g)MIL-101晶体。本文测定了苯和甲苯在MOF-5和MIL-101上的吸附等温线和甲苯在MIL-101上的吸附动力学曲线,估算了甲苯在MIL-101上的扩散系数和吸附活化能。结果表明:当T =时,苯和甲苯在MIL-101上的平衡吸附量分别为16.3 mmol/g和11.0 mmol/g,MIL-101晶体颗粒对苯和甲苯均有高效快速的吸附容量;甲苯在MIL-101上的吸附活化能为10.9 kJ/mol,大大低于其在活性炭上的吸附活化能。本文测定了甲苯在MIL-101上的程序升温脱附曲线,估算了甲苯在MIL-101材料上的脱附活化能,结果表明:甲苯在MIL-101上的脱附活化能为28.0 kJ/mol,大大低于其在其他吸附剂上的脱附活化能。以上结果表明,与传统吸附材料相比,MIL-101材料不仅对甲苯有很高的吸附容量和吸附速率,而且又能使甲苯较容易脱附,是一种很有前景的吸附VOCs材料。更多还原

【Abstract】 VOCs are a kind of environmental pollutant source which seriously threat human health and sustainable development of our society. Therefore, it is extremely urgent for us to effectively deal with VOCs. Adsorption technology is a technique which focuses on porous structured materials and is considered as one of the most potential technology for the air pollution treatment, so to develop new porous materials efficient to adsorb VOCs is the key point. This research mainly involves synthesis and characterization of MOF-5 and MIL-101, and measurements of their adsorption/desorption properties toward benzene and toluene. This study belongs to the fields of environmental engineering, chemical engineering and material engineering. It has important research significance and practical application background.The effects of synthesis condition on its physical properties of the MOF-5 crystals, including surface area and porous texture, were investigated. Results showed that the MOF-5 crystals whose particle sizes ranged from 20 to 60μm, surface area was up to 1022 m2/g and pore volume up to were obtained under the following conditions: synthesis temperature of 130℃, reaction time of 4 hours, the Zn2+/H2BDC molar ratio of 3, N, N-dimethylformamide as the solvent, certain purification and activating method.The effects of synthesis condition on its physical properties of the MIL-101 crystals including surface area, porous texture and so forth, were investigated. Results showed that high quality and purity MIL-101 crystals whose particle sizes ranged from 40-90 nm, surface area was up to 4443 m2/g and pore volume up to 1.89 cmwere obtained under the following conditions: synthesis temperature of 210℃, 1 hour’s microwave radiation, certain Cr3+/H2BDC/HF/H2O molar ratio, certain purification and activating method.Benzene and toluene adsorption isotherms and kinetic curves on the MOF-5 and the MIL-101 particles were determined, and the diffusivity coefficients and adsorption activation energy of toluene on MIL-101 were estimated. Results showed that the amounts adsorbed of benzene and toluene on the MOF-5 and the MIL-101 were up to 16.3 mmol/g and 11.0 mmol/g respectively at 298 K and p/pB0 B= 0.5, which showed that MIL-101 has higher adsorption capacities of both benzene and toluene; and the adsorption activation energy of toluene on the MIL-101 was 10.9 kJ/mol, which was obviously lower than that on activated carbon.TPD spectrums of toluene on the MIL-101 were determined, and then the desorption activation energy of toluene was estimated. Results showed that the desorption activation energy of toluene on the MIL-101 was 28.0 kJ/mol, which was obviously lower than that on other conventional adsorbents.The results above indicated that, the MIL-101 material not only had high adsorption capacity and adsorption rate for toluene in comparison with conventional adsorbents, but also had easily toluene desorb from it. It is a promising material for VOCs adsorption.更多还原