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金属有机骨架材料(Metal-organic frameworks,MOFs)因具有高的比表面积和孔隙率,使得其拥有良好的气体吸附性能.与传统的NOx吸附材料相比,MOFs材料拥有超高的比表面积和孔隙率,结构丰富多样且具有周期性,良好的热稳定性和化学稳定性.国内外学者采用不同的合成方法合成MOFs材料,以达到对NOx高效吸附的目的.MOFs材料的合成方法主要有水热法、溶剂热法、超声波合成法和微波合成法.水热法操作步骤简单,合成的晶体质量高,但是晶粒较大,孔体积小;溶剂热法和水热法原理相同,通过加入不同官能团的有机溶剂,合成的材料结构更为丰富,比表面积和孔容更大,对NOx的吸附效果比水热法好,也是使用最广泛的方法;超声波合成法合成的MOFs材料粒径较小且尺寸均一,比表面积和孔容较大,对NOx的吸附效果好,但是成本较高;微波合成法可加快反应速率,形成更小的晶粒,比表面积和孔容较大,对NOx的吸附量很高,但是同样也具有经济成本高的劣势.为此,本文对MOFs材料的合成方法、改性技术进行了总结,同时分析了不同方法合成的MOFs对氮氧化吸附效果的影响,并对MOFs材料吸附氮氧化物的发展趋势作了展望. 相似文献
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通过水热法合成铝基-金属有机骨架(MOFs)MIL-96材料,并将其作为吸附剂用于脱除水溶液中的萘。采用扫描电子显微镜、X射线衍射仪和N_2吸附-脱附等方法对材料进行表征。通过考察吸附动力学、吸附等温线以及热力学特征研究了MIL-96材料的吸附性能。研究结果表明:在温度298K、MIL-96材料用量为0.5g/L时,对萘的最大去除率达到约98%;MIL-96对萘的吸附特征符合准二级吸附动力学模型,Temkin和D-R等温吸附模型对萘吸附过程的描述比其他模型准确;Temkin等温吸附方程中吸附热相关系数表明,MIL-96吸附水溶液中萘的过程为吸热过程,热力学参数中正的标准焓变(ΔH~o)值也说明该吸附过程为吸热过程。 相似文献
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双过渡金属杂原子介观催化材料的制备及在有机合成中的应用 总被引:1,自引:0,他引:1
以煅烧偏高岭土为硅源,Na2MoO4为钼源,ZrO2为锆源,十六烷基三甲基溴化铵(CTAMB)为结构导向剂,利用水热法合成了规则六方结构的Zr-Mo-MCM-41介观催化材料。红外(FTIR)分析表明,799cm^-1处出现的伸缩振动峰可能为Zr-O键和Mo-O键的重叠峰。扫描电镜分析表明,合成的Zr-Mo-MCM-41催化材料的分散性能好,平均粒径在400nm左右且其颗粒为球形,这与X射线衍射(XRD)和激光粒度分析结果相一致.N2吸附脱附曲线研究表明,催化材料具有明显的介孔结构特征,孔径分布窄,在3.3nm左右。以H2O2为氧化剂,环戊烯环氧化反应作为探针反应,结果表明高有序介观催化材料Mo-Zr-MCM-41,与单一的杂原子Mo-MCM-41和Zr-MCM-41催化剂相比,在催化性能、水热稳定性、循环使用次数等方面得到明显改善,体现了双金属的催化协同效应。 相似文献
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Metal–organic frameworks (MOFs) have attracted considerable attention for various applications due to their tunable structure, porosity and functionality. In general, MOFs have been synthesized from isolated metal ions and organic linkers under hydrothermal or solvothermal conditions via one-spot reactions. The emerging precursor approach and kinetically tuned dimensional augmentation strategy add more diversity to this field. In addition, to speed up the crystallization process and create uniform crystals with reduced size, many alternative synthesis routes have been explored. Recent advances in microwave-assisted synthesis and electrochemical synthesis are presented in this review. In recent years, post-synthetic approaches have been shown to be powerful tools to synthesize MOFs with modified functionality, which cannot be attained via de novo synthesis. In this review, some current accomplishments of post-synthetic modification (PSM) based on covalent transformations and coordinative interactions as well as post-synthetic exchange (PSE) in robust MOFs are provided. 相似文献
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《Materials Research Bulletin》2013,48(11):4499-4505
The adsorption behavior of selected chloroaromatic compounds (chlorobenzene, 2-chlorotoluene, 1,3-dichlorobenzene, and 2-chloroanisole) over metal organic frameworks (MOFs) of MIL-125, NH2-MIL-125, UiO-66, MIL-101, and Cu3(BTC)2 were investigated. NH2-MIL-125 showed the highest adsorption capacity at 0.1 M, whereas MIL-101 showed the highest adsorption at 1.0 M, which was significantly higher than that of activated carbon under the given conditions. The equilibrium adsorption and kinetics data could be fitted well by the Langmuir model and pseudo-second-order kinetic model, respectively. The adsorption of 2-chloroanisole over NH2-MIL-125, MIL-101, and activated carbon was spontaneous and exothermic, and the randomness increased after adsorption. The adsorption rate constants increased with temperature and showed a dependence on the pore window size and surface functionality of the MOFs. NH2-MIL-125 and MIL-101 showed a preference for 2-chloroanisole in a mixture with other chloroaromatic compounds. The surface area and microporosity of the MOFs appear to be major factors governing the adsorption capacity of 2-chloroanisole. 相似文献
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Hao Li Kecheng Wang Yujia Sun Christina T. Lollar Jialuo Li Hong-Cai Zhou 《Materials Today》2018,21(2):108-121
Gas storage and separation are closely associated with the alleviation of greenhouse effect, the widespread use of clean energy, the control of toxic gases, and various other aspects in human society. In this review, we highlight the recent advances in gas storage and separation using metal-organic frameworks (MOFs). In addition to summarizing the gas uptakes of some benchmark MOFs, we emphasize on the desired chemical properties of MOFs for different gas storage/separation scenarios. Greenhouse gases (CO2), energy-related gases (H2 and CH4), and toxic gases (CO and NH3) are covered in the review. 相似文献
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