Preparation of highly water stable HKUST-1@Pyr composites for excellent CO2 capture capability and efficient separation of CO2/N2

In older to develop metal-organic framework (MOF) materials with exceptional CO2 capture ability and superior water stability, composites of HKUST-1@pyrrole (Pyr) were prepared using a rapid room temperature synthesis method. The samples were comprehensively characterized by various analytical instruments, including evaluation of gas adsorption capacity (CO2, CH4, and N-2), analysis of morphology, determination of pore size distribution, measurement of isosteric heat of adsorption, and assessment of water stability. The results revealed a close correlation between the presence of Pyr and the micropores and ultramicropores in the HKUST-1@Pyr composites. Notably, HKUST-1@Pyr(0.3) exhibited an impressive CO2 adsorption capacity of 3.19 mmol.g(-1) at 298 K and 100 kPa. Moreover, this composite demonstrated excellent selectivity for CO2/N-2 bicomponent gas (V:V = 15:85), surpassing that of HKUST-1 by 150%. Furthermore, it displayed remarkable water stability even after exposure to a 50% relative humidity (RH) environment for 15 days or immersed in a water solution for 6 h. Notably, it retained 84% of its initial adsorption capacity in 50% RH and 72% in a water solution, which outperforms pure HKUST-1 that retained only 28% and 13.8% respectively. More importantly, this study confirmed the potential of the Pyr-modified HKUST-1 composite as a promising material for gas adsorption and separation in humid environments.