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Published on: October 18, 2017
Selective Adsorption of Rare Earth Elements over Functionalized Cr-MIL-101
Yu-Ri Lee1, Kwangsun Yu1, Seenu Ravi1
1Department of Chemistry and Chemical Engineering , Inha University , Incheon , Republic of Korea.
This study developed novel chromium-based metal-organic frameworks (MOFs) for efficient rare earth element (REE) recovery. MIL-101-PMIDA demonstrated superior adsorption of REEs, particularly Gd3+, showcasing stability and recyclability for sustainable applications.
Area of Science:
- Materials Science
- Inorganic Chemistry
- Environmental Science
Background:
- Efficient separation and recovery of rare earth elements (REEs) are critical for high-tech industries.
- Existing methods face challenges in selectivity and sustainability.
- Metal-organic frameworks (MOFs) offer tunable properties for adsorption applications.
Purpose of the Study:
- To synthesize and evaluate chromium-based MOFs for REE separation and recovery.
- To investigate the adsorption performance of functionalized Cr-MIL-101 derivatives.
- To explore the adsorption mechanism and recyclability of the most effective MOF.
Main Methods:
- Synthesis of Cr-MIL-101 and its functionalized derivatives (MIL-101-NH2, MIL-101-ED, MIL-101-DETA, MIL-101-PMIDA).
- Characterization using various analytical techniques.
- Adsorption studies for La3+, Ce3+, Nd3+, Sm3+, and Gd3+ in aqueous solutions.
- Kinetic and isotherm modeling (Langmuir, pseudo-second-order).
- Adsorption mechanism investigation and recycling tests.
Main Results:
- MOFs exhibited increasing REE adsorption capacity in the order: MIL-101 < MIL-101-NH2 < MIL-101-ED < MIL-101-DETA < MIL-101-PMIDA.
- MIL-101-PMIDA showed superior adsorption, with Gd3+ being most efficiently adsorbed.
- Adsorption followed Langmuir and pseudo-second-order models, indicating surface complexation and electrostatic interactions.
- MIL-101-PMIDA demonstrated high structural stability over five adsorption-regeneration cycles.
Conclusions:
- Functionalized Cr-MIL-101, particularly MIL-101-PMIDA, is a promising material for selective REE separation and recovery.
- The phosphonomethyl iminodiacetic acid functional group significantly enhances adsorption capacity.
- The material's stability and recyclability support its potential for sustainable REE resource management.
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