(514b) Bi-Functionalized Ionic Liquid/MOF Composite Material for Efficient Carbon Dioxide Capture and Conversion

To alleviate environment issues derived from CO₂ emission, it is significant to develop an economical and effective means of CO₂ capture and conversion. Ionic liquids (ILs) possess remarkable properties such as low volatility, excellent thermal stability and widely tunable structure, which have been used as CO₂ absorbents and conversion catalysts. However, most of ionic liquids have the characteristic of high viscosity, which limits the mass transfer of guest molecules. Metal-organic framworks (MOFs) have recently attracted significant attention because of their large surface area, high porosity and inherent functionality. Therefore, combination of ILs and MOFs is a meaningful strategy to enhance capture ability and catalytic performance.

In this study, bi-functionalized ionic liquid immobilized on MOF material was developed for CO₂ capture and conversion. First, bi-functionalized ionic liquid 1-(2-carboxyl-ethyl)-3-methoxyethyl-imidazolium chloride ([CeMOEim][Cl]) and metal-organic framework MIL-53(Al) were respectively synthesized. Furthermore, [CeMOEim][Cl] was immobilized on as-synthesized MIL-53(Al) via ultrasonic-assisted impregnation method. Chemical structure, microstructure, and thermal stability of as-synthesized materials were characterized by NMR, FT-IR, XRD, SEM, TEM, N₂ adsorption-desorption measurement and TG analysis. Finally, [CeMOEim]/MIL-53(Al) composite materials with different loading rates were used as CO₂ sorbent and catalyst. For comparision, capture capacity and catalytic performance of the functionalized ionic liquid and MIL-53(Al) were also studied.