Volume 62, Issue 50 e202316149
Research Article

Synergistic Nitrogen Binding Sites in a Metal-Organic Framework for Efficient N2/O2 Separation

Dr. Feifei Zhang

Dr. Feifei Zhang

College of Chemistry and Chemical Engineering, Shanxi Key Laboratory of Gas Energy Efficient and Clean Utilization, Taiyuan University of Technology, Taiyuan, 030024 Shanxi Province, China

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Dr. Hua Shang

Dr. Hua Shang

College of Chemistry and Chemical Engineering, Shanxi Key Laboratory of Gas Energy Efficient and Clean Utilization, Taiyuan University of Technology, Taiyuan, 030024 Shanxi Province, China

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Bolun Zhai

Bolun Zhai

College of Chemistry and Chemical Engineering, Shanxi Key Laboratory of Gas Energy Efficient and Clean Utilization, Taiyuan University of Technology, Taiyuan, 030024 Shanxi Province, China

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Zhiwei Zhao

Zhiwei Zhao

College of Chemistry and Chemical Engineering, Shanxi Key Laboratory of Gas Energy Efficient and Clean Utilization, Taiyuan University of Technology, Taiyuan, 030024 Shanxi Province, China

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Dr. Yong Wang

Corresponding Author

Dr. Yong Wang

College of Chemistry and Chemical Engineering, Shanxi Key Laboratory of Gas Energy Efficient and Clean Utilization, Taiyuan University of Technology, Taiyuan, 030024 Shanxi Province, China

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Prof. Libo Li

Prof. Libo Li

College of Chemistry and Chemical Engineering, Shanxi Key Laboratory of Gas Energy Efficient and Clean Utilization, Taiyuan University of Technology, Taiyuan, 030024 Shanxi Province, China

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Prof. Jinping Li

Corresponding Author

Prof. Jinping Li

College of Chemistry and Chemical Engineering, Shanxi Key Laboratory of Gas Energy Efficient and Clean Utilization, Taiyuan University of Technology, Taiyuan, 030024 Shanxi Province, China

Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering, Taiyuan, 030024 Shanxi Province, China

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Prof. Jiangfeng Yang

Corresponding Author

Prof. Jiangfeng Yang

College of Chemistry and Chemical Engineering, Shanxi Key Laboratory of Gas Energy Efficient and Clean Utilization, Taiyuan University of Technology, Taiyuan, 030024 Shanxi Province, China

Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering, Taiyuan, 030024 Shanxi Province, China

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First published: 07 November 2023
Citations: 13

Graphical Abstract

A synergistic nitrogen binding site is constructed using adjacent open Cr(III) and F in a metal-organic framework (MOF). It gives benchmark N2/O2 selectivity and the highest high-purity oxygen productivity reported to date.

Abstract

Porous materials with d3 electronic configuration open metal sites have been proved to be effective adsorbents for N2 capture and N2/O2 separation. However, the reported materials remain challenging to address the trade-off between adsorption capacity and selectivity. Herein, we report a robust MOF, MIL-102Cr, that features two binding sites, can synergistically afford strong interactions for N2 capture. The synergistic adsorption site exhibits a benchmark Qst of 45.0 kJ mol−1 for N2 among the Cr-based MOFs, a record-high volumetric N2 uptake (31.38 cm3 cm−3), and highest N2/O2 selectivity (13.11) at 298 K and 1.0 bar. Breakthrough experiments reveal that MIL-102Cr can efficiently capture N2 from a 79/21 N2/O2 mixture, providing a record 99.99 % pure O2 productivity of 0.75 mmol g−1. In situ infrared spectroscopy and computational modelling studies revealed that a synergistic adsorption effect by open Cr(III) and fluorine sites was accountable for the strong interactions between the MOF and N2.

Conflict of interest

The authors declare no conflict of interest.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

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