A Novel Mesoporous Aluminum-Based MOF with Large Pore Volume for High Concentration Benzene Adsorption

Developing large pore volume mesoporous metal-organic frameworks (MOFs) is a reliable strategy for adsorbing high-concentration benzene in the event of accidental leakage. Herein, a novel mesoporous Al-based MOF, named ZJU-928(Al), is synthesized using biphenyl-3,4′,5-tricarboxylic acid ligands and low toxic AlO₆ cluster. It has larger pore volume (1.05 cm³ g⁻¹), order hexagonal channel (32.10 Å), and higher specific surface area (2344 m² g⁻¹). As relative pressure up to 0.10, benzene adsorption of ZJU-928(Al) rises to 9.99 mmol g⁻¹, exhibiting an excellent saturation benzene adsorption of 11.37 mmol g⁻¹ at 298 K. The isosteric heat of adsorption for benzene on ZJU-928(Al) is only 24.52 kJ mol⁻¹ at near-zero loading, lower than that of most reported MOFs, allowing for lower energy consumption during ZJU-928(Al) regeneration. ZJU-928(Al) has excellent cyclical benzene adsorption-desorption performance, and highest benzene diffusivity coefficient (2.65 × 10⁻⁵ cm² s⁻¹). Simulation shows that the excellent saturation benzene adsorption performance of ZJU-928(Al) can be attributed to the larger pore volume accommodating more benzene molecules. Consequently, this research synthesizes a novel mesoporous Al-based MOF with excellent saturation benzene adsorption, highlighting the potential of MOFs for high-concentration toxic gas adsorption.