(2016) Scientific Reports_Metal organic frameworks as sorption media for volatile and semi-volatile organic compounds at ambient conditions

Vellingiri K., Szulejko J.E., Kumar P., Kwon E.E., Kim K.-H., Deep A., Boukhvalov D.W., Brown R.J.C.

(Nature Publishing Group) Scientific Reports ISSN: 20452322 Vol.6 Issue. Article No.27813 DOI: 10.1038/srep27813

In this research, we investigated the sorptive behavior of a mixture of 14 volatile and semi-volatile organic compounds (four aromatic hydrocarbons (benzene, toluene, p-xylene, and styrene), six C₂-C₅ volatile fatty acids (VFAs), two phenols, and two indoles) against three metal-organic frameworks (MOFs), i.e., MOF-5, Eu-MOF, and MOF-199 at 5 to 10 mPa VOC partial pressures (25 °C). The selected MOFs exhibited the strongest affinity for semi-volatile (polar) VOC molecules (skatole), whereas the weakest affinity toward was volatile (non-polar) VOC molecules (i.e., benzene). Our experimental results were also supported through simulation analysis in which polar molecules were bound most strongly to MOF-199, reflecting the presence of strong interactions of Cu²⁺ with polar VOCs. In addition, the performance of selected MOFs was compared to three well-known commercial sorbents (Tenax TA, Carbopack X, and Carboxen 1000) under the same conditions. The estimated equilibrium adsorption capacity (mg.g^-1) for the all target VOCs was in the order of; MOF-199 (71.7), Carboxen-1000 (68.4), Eu-MOF (27.9), Carbopack X (24.3), MOF-5 (12.7), Tenax TA (10.6). Hopefully, outcome of this study are expected to open a new corridor to expand the practical application of MOFs for the treatment diverse VOC mixtures.