Abstract
Microporous organic polymers (MOPs) are promising materials for gas sorption because of their intrinsic and permanent porosity, designable framework, and low density. The introduction of nitrogen-rich building block in MOPs will greatly enhance the gas sorption capacity. Here, we report the synthesis of MOPs from the 2,4,6-tris(4-ethynylphenyl)-1,3,5-triazine unit and aromatic azides linkers by click polymerization reaction. Fourier transform infrared (FTIR) and solid-state (13)C CP-MAS (Cross Polarization-Magic Angle Spinning) NMR confirm the formation of the polymers. CMOP-1 and CMOP-2 exhibit microporous networks with a BET (Brunauer⁻Emmett⁻Teller) surface area of 431 m²·g(-1) and 406 m²·g(-1) and a narrow pore size distribution under 1.2 nm. Gas sorption isotherms including CO₂ and H₂ were measured. CMOP-1 stores a superior CO₂ level of 1.85 mmol·g(-1) at 273 K/1.0 bar, and an H₂ uptake of up to 2.94 mmol·g(-1) at 77 K/1.0 bar, while CMOP-2, with its smaller surface area, shows a lower CO₂ adsorption capacity of 1.64 mmol·g(-1) and an H₂ uptake of 2.48 mmol·g(-1). In addition, I₂ vapor adsorption was tested at 353 K. CMOP-1 shows a higher gravimetric load of 160 wt%. Despite the moderate surface area, the CMOPs display excellent sorption ability for CO₂ and I₂ due to the nitrogen-rich content in the polymers.