A novel amino-functionalized Bio-MOF for trace SO2 adsorption under dry and humid conditions

Sulfur dioxide (SO 2 ) adsorption, from the exhaust gas of the industrial processes and vehicles, remains an issue due to the corrosive nature of SO 2 . Herein, a novel amino-functionalized bio-derived metal–organic framework, named Bio-ZJU-928(Ni), comprises “paddle-wheel” shaped nickel secondary building unit, acetic acid ligand, and adenine with amino group. It exhibits excellent chemical-thermal stability, specific surface area (634 m 2 g −1 ), outstanding trace SO 2 adsorption (2.94 mmol g −1 ) at 0.002 bar and 273 K, and good cyclical SO 2 adsorption–desorption performance. Bio-ZJU-928(Ni) also has excellent SO 2 selectivity adsorption, identified by its higher ideal adsorption solution theory values for SO 2 /N 2 (32,145) and SO 2 /CO 2 (259.35) at 10/90 ( v/v ) and 273 K, respectively. Under relative humidity (50 %), the dynamic SO 2 adsorption of Bio-ZJU-928(Ni) is 32.47 cm 3 g −1 , which is higher than that of Bio-ZJU-928(Ni) under dry condition (23.08 cm 3 g −1 ) at the mixture gases (N 2 /CO 2 /O 2 /SO 2  = 81.8:15:3:0.2). The enhanced SO 2 adsorption of Bio-ZJU-928(Ni) can be ascribed to the O=S=O···H − O hydrogen bond formed with water, as verified by in situ diffuse reflectance infrared Fourier transform spectroscopy and Grand canonical Monte Carlo simulations