Abstract
•Synthesis Conditions: Various synthesis conditions significantly influence the material's structural stability, porosity, CO2 uptake, morphology, and surface area.•CO2 Adsorption Capacity: Material synthesized at elevated temperature (125 °C) yielded the maximum CO2 adsorption capacity of up to 31 cm³/g.•Practical Applications: The evaluated physicochemical properties of the material demonstrated the material’s suitability to for CO2 capture applications.
The growing global concern over greenhouse gas emissions, specifically carbon dioxide (CO2), has led to extensive research efforts to develop innovative materials and technologies to combat the impacts of climate change. Among these materials, metal-organic frameworks (MOFs) have received significant attention in science due to their distinctive structural and adsorption properties. Within this context, magnesium-based-MOF-74 (Mg-MOF-74) has emerged as a potential candidate for efficient post-combustion CO2 capture. Mg-MOF-74 is a porous material that significantly removes CO2 from gas mixtures by adsorption. Its porous structure, with accessible magnesium ions, enables selective CO2 binding. The MOF has a high selectivity for CO2 and may be reused with heat or pressure adjustments. This study undertakes a comprehensive exploration of the synthesis, characterization, and potential practical applications of Mg-MOF-74, with a particular emphasis on the effect of synthesis conditions on the material’s efficacy as a sustainable solution for reducing CO2 emissions from typical coal-fired power plants.
The synthesis of Mg-MOF-74 was conducted at various reaction temperatures (100 °C, 110 °C, and 125 °C) and time (8 and 24 h). Characterization techniques employed include X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA), Fourier-Transform Infrared Spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) surface area analysis, and Scanning Electron Microscopy with Energy-Dispersive X-ray Spectroscopy (SEM-EDX). The XRD data highlight temperature and time effects on crystallinity, with 100 °C for 24 h yielding well-defined structures indicating higher crystallinity than other conditions. The TGA revealed that the synthesized material is thermally stable up to 600 °C. The FTIR analysis identifies critical functional groups, such as C = O, Mg-O, and C = C groups, oxygen-containing functional groups are prime for CO2 capture. The low-pressure gas nitrogen gas adsorption (BET) study revealed Type III isotherms, signifying microporous and mesoporous features with maximum BET surface area of 24 m2/g, Langmuir surface area of 612 m2/g and varying pore sizes ranging between 8.48 and 10.13 nm. Low-pressure gas adsorption (LPGA) using CO2 gas was used to evaluate the materials' adsorption capacity. Results showed that increasing the synthesis temperature to 125 °C increased the adsorption capacity to a maximum of 31 cm3/g. The SEM micrographs display diverse morphologies with irregular patterns and cloud-like structures across samples.
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