Improving CO_2/CH_4 and CO_2/N_2 adsorptive selectivity of Cu-BTC and MOF-derived nanoporous carbon by modification with nitrogen-containing groups

摘要

For the first time in this study compared the adsorption capacity and selectivity of carbon dioxide (CO_2), methane (CH_4), and nitrogen (N_2) on amine-modified copper(ll) benzene-1,3,5-tricarboxylate (Cu-BTC) and metal organic framework-derived nanoporous carbon (MOF/NPC) by employing a volumetric measurement. The MOF/NPC is synthesized via direct carbonization of the Cu-BTC as a template without any carbon precursor at 900° C under N_2 atmosphere and shows easy synthesis, large surface area, high excellent thermal and chemical stability as well as high resistance to moisture. All the prepared materials are characterized by nitrogen adsorption/desorption, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and thermogravimetric analysis (TGA). The porous supports could be effectively improved for CO_2 adsorption with amine groups due to their high affinity toward CO_2. CO_2 adsorption capacity for MOF/NPC is 7.50 mmol g~(-1) when MOF/NPC is modified with the amine, CO_2 adsorption capacity is increased (from 7.50 to 11.40 mmol g~(-1) at 298 K and 10 bar.