Modelling toluene sorption in ionic liquid/metal organic framework composite materials

Ventura Castillo Ramos; Wei Han; Xiangping Zhang; Suojiang Zhang; King Lun Yeung

doi:10.1016/j.envres.2022.115000

Modelling toluene sorption in ionic liquid/metal organic framework composite materials

Environ Res. 2023 Feb 15:219:115000. doi: 10.1016/j.envres.2022.115000. Epub 2022 Dec 16.

Authors

Ventura Castillo Ramos¹, Wei Han², Xiangping Zhang³, Suojiang Zhang³, King Lun Yeung⁴

Affiliations

¹ Department of Inorganic Chemistry, Faculty of Science, University of Granada, Granada, Spain; Division of Environment and Sustainability, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong Special Administrative Region. Electronic address: vcastillo@ugr.es.
² Division of Environment and Sustainability, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong Special Administrative Region; HKUST Shenzhen-Hong Kong Collaborative Innovation Research Institute, Futian, Shenzhen, Guangdong Province, China.
³ Beijing Key Laboratory of Ionic Liquids Clean Process, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China.
⁴ Division of Environment and Sustainability, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong Special Administrative Region; HKUST Shenzhen-Hong Kong Collaborative Innovation Research Institute, Futian, Shenzhen, Guangdong Province, China; Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong Special Administrative Region.

PMID: 36529328
DOI: 10.1016/j.envres.2022.115000

Abstract

Toluene is a prevalent pollutant in indoor environments and its removal is essential to maintain a healthy environment. Adsorption is one of the best alternatives for organic vapours removal, specially at low indoor concentrations. Metal Organic Frameworks (MOFs) and Ionic Liquids (ILs) are potential materials for this mean. In this work, the synthesis and application of IL/MOF composite materials for toluene removal is reported. Loading [BMIM][CH₃COO] ionic liquid into MIL101 porous structure improves parent materials affinity towards toluene capture by two orders of magnitude (as Henry's constants, attesting to their synergy). MIL101(Cr) and absorption in [BMIM][CH₃COO] IL is best described by Henry's Law, while the Langmuir adsorption model predicts toluene adsorption on [BMIM][CH₃COO]/MIL101(Cr) better than Freundlich and Toth equations. Diffusional and kinetics models revealed that toluene diffusion is the rate limiting step for pristine MIL101. Kinetic and diffusion rates were systematically improved upon the incorporation of the ionic liquid due to shorter toluene hops with the adsorbed IL and the increased hydrophobicity in the composites making the sorption more favourable. This study provides a systematic analysis and modelling of the toluene capture process in IL/MOF composites aiding a better understanding of the sorption process in these novel materials.

Keywords: Ionic liquid; Isotherms; Kinetics; Metal organic framework; Toluene.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Environmental Pollutants*
Gases
Ionic Liquids* / chemistry
Metal-Organic Frameworks*
Toluene / chemistry

Substances

Metal-Organic Frameworks
Toluene
Ionic Liquids
Environmental Pollutants
Gases