Maximizing the Density of Active Groups in Porous Poly(ionic liquids) for Efficient Adsorptive Desulfurization

Porous poly(ionic liquids) (PPILs) with both advantages of ionic liquids (ILs) activities and porous properties have caused great interests in adsorptive desulfurization. High density of active functional groups and large surface area in PPILs are two critical factors for enhancing the desulfurization performance; however, there is usually a trade-off between them. In this work, a novel PPIL of poly(bipropargyl-imidazolium chloride) (P[BPPIM]) was fabricated through a single-step cyclotrimerization homopolymerization. Through this full-atomic utilization method, the mass density of active imidazolium groups were maximized; meanwhile, the introduction of rigid benzene rings within imidazolium rings propped up the porous structure in P[BPPIM], with a surface area of 160.8 m 2 ·g –1 and pore volume of 0.39 cm 3 ·g –1 . On the basis of the density function theory calculation, the binding energies of dibenzothiophene (DBT) over P[BPPIM] were significantly increased due to the synergistic effect of the imidazolium ring and benzene ring, resulting in an enhanced saturated DBT adsorption capacity of 37.13 mgS·g –1, which was the best one among all the reported PILs according to our knowledge.