Coal-fired power generation remains a major source of carbon dioxide (CO₂) emissions, and metal–organic framework-74 (MOF-74) materials offer high adsorption capacity but rely on costly 2,5-dihydroxyterephthalic acid linkers that limit scalability. This study synthesized bimetallic Zn_0.75Mg_0.25-MOF-74 using terephthalic acid (TPA) as a cheaper alternative linker and evaluated the effect of synthesis reaction temperature (89–160 °C) and time (5–55.5 h) on its physicochemical properties for carbon capture. Samples were prepared solvothermally and characterized by FTIR, XRD, SEM-EDS, and N₂ (77 K) and CO₂ (293 K) adsorption analysis. FTIR confirmed metal–ligand coordination; XRD verified crystalline MOF-74 formation, and SEM showed well-defined rod-like morphology at 100 °C, 12 h and 125 °C, 30 h. Direct CO₂ adsorption on the 125 °C, 30 h sample yielded a Type I isotherm characteristic of micropore filling, with an uptake of 0.31 mmol/g at ~1 bar and 0.072 mmol/g at flue-gas-relevant conditions (~0.135 bar). Its CO₂-derived BET surface area (60.10 m²/g) and Dubinin–Astakhov micropore area (131.69 m²/g) far exceeded N₂-derived values, confirming ultra-micropores accessible to CO₂ but not to N₂ at 77 K. TPA therefore yields a stable, microporous CO₂-adsorbing framework, trading some capacity for lower cost and scalability. Future investigations should systematically evaluate long-term cycling stability and adsorption performance under mixed-gas operating conditions.

The urgent need to mitigate carbon dioxide (CO₂) emissions from fossil-fuel-based electricity generation has driven research into advanced materials for post-combustion carbon capture. This paper presents a modified solvothermal technique to synthesize zinc (Zn) and magnesium (Mg) based MOF-74 suitable for CO₂ capture from coal-fired power plants. The materials were synthesized through a solvothermal method using N,N-dimethylformamide (DMF) as the primary solvent, and subsequently characterized using Brunauer–Emmett–Teller (BET) surface area analysis, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), and thermogravimetric analysis (TGA). Both MOFs contained oxygen-containing functional groups and were thermally stable up to 430 °C and 600 °C respectively, making them ideal for carbon capture. The low-pressure N₂-BET surface areas were 55 m²/g and 24.73 m²/g. In conclusion, the Zn material had a mesoporous structure, making it more favorable for carbon capture. It was found that prolonged synthesis time weakened the MOF structure. Future work should experimentally evaluate CO₂ capture from coal-derived flue gas using Zn/Mg-MOF-74 materials, investigating adsorption behavior and kinetics through isotherm and kinetic models, while also assessing the effect of varying Zn: Mg ratios under optimized synthesis conditions.

Carbon capture and storage (CCS) is a climate change mitigation technique in which CO₂ is captured from a point source, including coal-fired power plants and other industrial activities, rather than released into the atmosphere