Synthesis and characterization of mesoporous MOF UMCM-1 for CO2/CH4 adsorption; an experimental, isotherm modeling and thermodynamic study

摘要

In this work, a metal-centered organic framework (UMCM-1) demonstrating microporous nature was prepared by the combination of the organic linker 1,3,5-tris(4-carboxyphenyl) benzene (H2BTB) and the salt Zinc Nitrate Hexahydrate (Zn-(NO3)(2)center dot 6H(2)O) via solution-based, catalyst-free, and direct mixing method. The structural characteristics and porous properties of UMCM-1 were investigated by surface morphology, functional groups analysis, crystallinity, thermal stability, texture characteristics via FESEM, FTIR, PXRD, thermal stability analysis, porous properties, respectively, and pure gases (CO2 and CH4) uptake behaviour. The pure CO2 and CH4 adsorption were acquired out at a pressure of 1 bar and at three various temperatures i.e. 298.15 K, 323.15 K, and 348.15 K. The N-2 adsorption-desorption isotherms reveal their highly microporous nature with specific surface area (3481.0667 m(2)/g), pore size (19.9373 angstrom), and the pore volume (0.0178 cm(3)/g). The UMCM-1 was found crystalline and highly stable under harsh thermal conditions. The CO 2 uptake capacity (1.0732 mmol/g) was found to be 138.48% approximately higher than CH 4 uptake capacity (0.45 mmol/g). By increasing temperature, 10.7% approximately loss in the uptake capacities of CO2 and CH4 was observe demonstrating the exoergic in nature i.e. energy-releasing adsorption phenomenon. Furthermore, the isotherms and thermodynamic study demonstrated that the adsorption phenomenon is favorable adsorption behaviour with the heterogeneous system, demands higher pressure adsorption to activate the pores and physical in nature. The results presented herein demonstrated the UMCM-1 as a promising candidate for the energy-efficient CO2 separation.