Adsorption and Separation of Small Hydrocarbons on the Flexible, Vanadium-Containing MOF, COMOC-2
Adsorption and Separation of Small Hydrocarbons on the Flexible, Vanadium-Containing MOF, COMOC-2
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柔性含钒 MOF（COMOC-2）上小分子烃的吸附和分离
DOI：
10.1021/acs.langmuir.5b00655
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发表时间：
2015-05-12
期刊：
影响因子：
3.9
通讯作者：
Denayer, Joeri F. M.
中科院分区：
文献类型：
--
作者：
Couck, Sarah;Van Assche, Tom R. C.;Denayer, Joeri F. M.
研究了柔性含钒金属有机骨架COMOC-2对轻烃的吸附和分离性能。COMOC-2是MIL-47骨架的扩展版本，用4，4‘-联苯二甲酸取代了对苯二甲酸。在281~303K温度范围内，用重量吸附技术测定了甲烷在丙烷、乙烯和丙烯上的吸附等温线。观察到了明显的呼吸效应(与更坚硬的MIL-47骨架相反)，在给定的呼吸压力下，吸附容量增加了2倍以上。呼吸压力随烃类分子量的增加而降低。根据物质的非极性性质，烷烃和烯烃的典型两步等温线几乎相同。用重量吸收技术测定了不同温度和总压下的乙烷和丙烷的二元等温线。根据渗透骨架吸附溶液理论(OFAST)预测了混合液的等温线和呼吸转变压。最后，通过不同组成和不同压力下的突破实验，考察了COMOC-2对乙烷/丙烷混合物的分离潜力。
COMOC-2, a flexible vanadium-containing metal, organic framework, was investigated for its adsorption and separation properties of light hydrocarbons, COMOC-2 is an extended version of the MIL-47 framework with 4,4'-biphenyldicarboxylic acid linkers instead of tetephthalic acid. Adsorption isotherms of methane to propane, ethylene, and propylene were determined with a gravimetric uptake technique at temperatures between 281 and 303 K. A pronounced breathing effect was observed (in contrast to the more rigid MIL-47 framework) in which the adsorption capacity increases by more than a factor of 2 at a given breathing pressure. The breathing pressure decreases with increasing hydrocarbon molecular weight. The typical two-step isotherms are nearly identical for alkanes and alkenes, hi accordance with the nonpolar nature of the material. Binary isotherms of ethane and propane were also measured with the gravimetric uptake technique at different temperatures and total pressures. The mixture isotherms and breathing transition pressures were predicted by relying on the osmotic framework adsorbed solution theory (OFAST). Finally, the separation potential of COMOC-2 for ethane/propane mixtures was looked into using breakthrough experiments for different compositions and different pressures.