Synthesis of ultra-porous zeolitic imidazolate Framework-300 under different synthesis conditions for sorption of CO2

• Published in: Journal of solid state chemistry 2024-07, Vol.335, p.124700, Article 124700
• Main Authors: Jomekian, Abolfazl, Bazooyar, Bahamin
• Format: Article
• Language: English
• Subjects: Precursors molar ratio; Synthesis environment; Temperature; Time; ZIF-300
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/j.jssc.2024.124700

We examined here how different ratios of precursors, temperature, time, and synthesis environment affected the crystal structure, texture, and CO2/N2 sorption behavior of the ZIF-300 samples synthesized. We found that a higher bmim/meIm molar ratio resulted in larger particle size, increased pore volume, and higher BET surface area due to a more crystalline structure and well-shaped pore structure. This was attributed to a decrease in the pH of the synthesis solution caused by the higher bmim/meIm molar ratio, which lowered the ζ potential and reduced electrostatic repulsion between particles, leading to the formation of larger particles with a more crystalline structure. Increasing the temperature of the synthesis solution resulted in smaller particles due to a decrease in supersaturation levels and the formation of smaller nuclei. The duration of synthesis had a positive effect on particle size as both growth and aggregation of smaller particles occurred over time. NMP and DMA were found to be unsuitable synthesis environments as they produced large particles with poor gas sorption performance. In terms of texture, ZIF-300 samples synthesized with a higher bmim/meIm molar ratio and at lower temperatures exhibited higher BET surface area and pore volume compared to other samples. Additionally, samples synthesized with a molar ratio of bmim/meIm = 4/1 and 2/1 showed better selectivity for CO2/N2 solubility compared to similar cases reported in previous studies. Effect of different ratios of precursors, temperature, time, and synthesis environment on crystal structure and textural behavior of the different ZIF-300 samples. [Display omitted] •Factors studied on ZIF-300 samples: crystal structure, texture, CO2/N2 sorption behavior.•Higher bmim/meIm ratio = larger particle size, increased pore volume, higher BET surface area.•Higher synthesis temperature = smaller particles due to decreased supersaturation levels.•Longer synthesis duration = positive effect on particle size due to growth and aggregation.•NMP and DMA unsuitable synthesis environments: large particles, poor gas sorption performance.