1 SCIENTIFIC REPORTS | 6:27813 | DOI: 10.1038/srep27813 www.nature.com/scientificreports Metal organic frameworks as sorption media for volatile and semi-volatile organic compounds at ambient conditions Kowsalya Vellingiri 1 , Jan E. Szulejko 1 , Pawan Kumar 2 , Eilhann E. Kwon 3 , Ki-Hyun Kim 1 , Akash Deep 4 , Danil W. Boukhvalov 5 & Richard J. C. Brown 6 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 C 2 -C 5 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 Cu 2+ 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. Emissions of volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs: volatile fatty acids (VFAs), phenolic, and indolic compounds) and their resulting impact on human health are a major environ- mental concern 1–3 . Exposure of many of these pollutants has indeed been identified as the causes of diverse (both acute and chronic) health problems 4 . To date, many types of conventional technologies employing diverse classes of materials (e.g., activated carbon, zeolites, and hybrid materials) have been tested for their feasibility toward chemical and physical sorption applications 5 . ese technologies have a number of shortcomings or limitations including limited adsorption capacity, toxic end products, and high energy costs for regeneration 6 . In pursuit of a viable means to resolve such problems, the potent role of metal organic frameworks (MOFs) has been recognized due to many advantageous features including high surface area, enhanced gas/vapor adsorption, high catalytic activity, thermal/chemical stability, and tailorable pore sizes. As such, MOFs can be used as excellent adsorbent materials to treat diverse VOCs and VFAs 7,8 . In recent years, the use of pendant and incorporated functional groups (e.g., carboxyl) during post and pre-synthesis has been demonstrated as a simple methodology for increasing adsorption/removal capacity and selectivity toward various gaseous and aqueous phase pollutants 9–13 . For example, MOF-199 exhibited good adsorption capacity for benzene as 511 mg g −1 at 308 K (1.5 mbar partial pressure and 34% relative humidity (RH)) 14 . Likewise, NENU-511 was estimated to have adsorption capacity for benzene as 1.56 g.g −1 (or 0.61 g.mL −1 ) at its saturated vapor pressure 15 . e adsorption capacity (mg g −1 ) of toluene and p-xylene on MIL-101 was 1 Department of Civil and Environmental Engineering, Hanyang University, 222, Wangsimni-Ro, Seoul 04763, Korea. 2 Department of Chemical Engineering, Indian Institute of Technology, Hauz Khas, New Delhi 110 016, India. 3 Department of Environment and Energy, Sejong University, Seoul 05006, Republic of Korea. 4 CSIR-Central Scientific Instrument Organisation (CSIR-CSIO), Chandigarh 160030, India. 5 Department of Chemistry, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 04763, Korea. 6 Environment Division, National Physical Laboratory, Teddington, Middlesex, TW11 0LW, UK. Correspondence and requests for materials should be addressed to K.-H. Kim (email: kkim61@hanyang.ac.kr) Received: 04 April 2016 Accepted: 25 May 2016 Published: 21 June 2016 OPEN