Adsorption performance and kinetic study of hierarchical porous Fe-based MOFs for toluene removal

Xiaoling Ma; Wenlong Wang; Chenggong Sun; Hui Li; Jing Sun; Xin Liu

doi:10.1016/j.scitotenv.2021.148622

Adsorption performance and kinetic study of hierarchical porous Fe-based MOFs for toluene removal

Sci Total Environ. 2021 Nov 1:793:148622. doi: 10.1016/j.scitotenv.2021.148622. Epub 2021 Jun 22.

Authors

Xiaoling Ma¹, Wenlong Wang², Chenggong Sun³, Hui Li⁴, Jing Sun¹, Xin Liu⁵

Affiliations

¹ National Engineering Laboratory for Reducing Emissions from Coal Combustion, Engineering Research Center of Environmental Thermal Technology of Ministry of Education, Shandong Key Laboratory of Energy Carbon Reduction and Resource Utilization, School of Energy and Power Engineering, Shandong University, Jinan, Shandong 250061, PR China.
² National Engineering Laboratory for Reducing Emissions from Coal Combustion, Engineering Research Center of Environmental Thermal Technology of Ministry of Education, Shandong Key Laboratory of Energy Carbon Reduction and Resource Utilization, School of Energy and Power Engineering, Shandong University, Jinan, Shandong 250061, PR China. Electronic address: wwenlong@sdu.edu.cn.
³ Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, UK. Electronic address: Cheng-Gong.Sun@nottingham.ac.uk.
⁴ School of Thermal Engineering, Shandong Jianzhu University, Jinan 250101, PR China.
⁵ Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, UK.

PMID: 34328958
DOI: 10.1016/j.scitotenv.2021.148622

Abstract

In light of the promising merits of large surface area, uniform pore size, and tunable functional groups, metal-organic frameworks (MOFs) have great potential to be utilized for adsorbing volatile organic compounds (VOCs). In this study, three Fe-based MOFs, MIL-100(Fe), MIL-101(Fe), and MIL-53(Fe), were synthesized systematically and used to adsorb a typical VOC, toluene. Static adsorption, dynamic breakthrough curves, and adsorption kinetics were conducted to assess the adsorption performance. Additionally, the surface functional groups, pore structure, and morphology were systematically characterized by means of XRD, SEM, XPS, FTIR and N₂ adsorption-desorption analyses to reveal the cause of the difference in adsorption of these Fe-based MOFs. The results revealed that the maximum equilibrium adsorption capacity of 663 mg/g was achieved by MIL-100(Fe) with the highest specific surface area and pore volume. The dynamic adsorption of toluene on MIL-100(Fe) was in accordance with the pseudo-first order kinetic model and the Langmuir isothermal model. The formed π-π stacking interaction between organic ligands and the benzene ring in the MIL-100(Fe) cluster is the primary adsorption mechanism based on XPS analysis. Moreover, MIL-100(Fe) was easily regenerated via microwave irradiation with a negligible adsorption capacity decrease after three cycles. This work highlights the feasibility of hierarchical porous Fe-based MOFs as toluene adsorbents and promotes the application of MOFs in the field of pollution control.

Keywords: Hierarchical porous; MOFs; Regeneration; Toluene adsorption; VOCs.

MeSH terms

Adsorption
Kinetics
Metal-Organic Frameworks*
Porosity
Toluene

Substances

Metal-Organic Frameworks
Toluene