In-situ amino-functionalization of zeolitic imidazolate frameworks for high-efficiency capture of low-concentration CO2 from flue gas

The capture of low-concentration CO2 from flue gas is an on-going challenge. In this work, a novel series of amino-functionalized zeolitic imidazolate framework-8 materials (ZIF-DIA) was facilely synthesized via in-situ incorporating an large-size amino-functional imidazolium ligand during the synthesis process under atmospheric conditions, and its adsorption performance of CO2 from a simulated flue gas (15 vol% CO2) was investigated. With the introduction of amino-functional imidazolium ligand, the regular hexahedron structure of pure ZIF-8 is gradually converted into cluster-like morphology. The amino-functionalized ZIF materials exhibit high specific surface areas (712-941 m(2).g(-1)), rapid CO2 adsorption rate (<80 s), excellent CO 2 adsorption capacities of up to 6.17 mmol.g(-1) under wide temperature range (35-110 degrees C), overwhelming that of pure ZIF-8 (<= 1.96 mmol.g(-1)) and other reported metal-organic frameworks (MOFs). DFT calculation verified that pi-pi stacking and hydrogen bonding between imidazole/aromatic rings on ligands and CO2 play crucial role in high CO2 uptake. Excellent recyclability in 10 runs under both low and high temperatures (55 degrees C, 110 degrees C) is exhibited, endowing this kind of materials with great potential for practical applications.

Automated summary

This work focuses on the synthesis of a novel series of amino-functionalized zeolitic imidazolate framework-8 materials (ZIF-DIA) to address the challenge of capturing low-concentration CO2 from flue gas. The amino-functionalized ZIF materials exhibit high specific surface areas, rapid CO2 adsorption rate, excellent CO2 adsorption capacities, and excellent recyclability, showing great potential for practical applications.