CO 2 Adsorption on Organic-Inorganic Hybrids with the Addition of ZSM-5

Introduction: Compared to amine solvents for CO2 absorption, highly nanoporous materials have the advantages of easy handling, high efficiency, and environmentfriendly. Organic-inorganic hybrids, a class of porous materials formed by the selfassembly of metal ions and organic ligands, stand out as promising candidates for CO2 adsorption due to large porosities and structural tunabilities. Methods: Organic-inorganic hybrids of Cu (dhbc)2bpy were synthesized with 2,5- dihydroxy benzoic acid, 4’4 bpy, Cu(NO3)2, and C2H6O. The ZSM-5/Cu(dhbc)2bpy composites were obtained with the addition of ZSM-5 during Cu(dhbc)2bpy synthesis. The structures and morphologies of samples were studied with X-ray powder diffraction, Fourier transform infrared spectroscopy, N2 adsorption and desorption at 77 K, field emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy, respectively. The CO2 adsorption on the samples was down at 273 K. Results: CO2 adsorption amount of ZSM-5/Cu(dhbc)2bpy composites at 273 K and P/P0=0.03 was 2.2 mmol/g higher than that of Cu(dhbc)2bpy, which was 1.70 mmol/g. Discussion: ZSM-5/Cu(dhbc)2bpy composites contained 1.0 wt.% ZSM-5. The materials were of micro- and mesopores. In the preparation of the samples, the crystalline structure of Cu(dhbc)2bpy was unchanged in the presence of ZSM-5. The hierarchical porous structures and protonic hierarchical crystalline frameworks of the materials could account for their high CO2 uptake. Conclusion: ZSM-5/Cu(dhbc)2bpy composites were prepared in one step. The materials showed an enhanced CO2 adsorption with the addition of ZSM-5 into Cu(dhbc)2bpy, suggesting a new approach towards effective CO2 adsorption on organic-inorganic hybrids with the addition of zeolites.