Carbon dioxide capture and sequestration (CCS) has undoubtedly been at the forefront over the last decade in order to mitigate greenhouse gas problem, leading to many efforts to tackle the growing crisis by developing efficient materials and technologies. Nanoporous polymeric networks, crystalline or amorphous, have been studied extensively for gas storage and separation, and the porous structures containing diverse organic functionalities allow to control chemistry and porosity of materials for selective and enhanced CO2 capture. Recently, metal-functionalized porous polymers have demonstrated that the use of metal ions in the networks improves gas sorption capacities, since metal ions provide an active center for gas molecule adsorption. In this regard, we developed salophen-based covalent organic polymers (S-COPs) and metal-incorporated S-COPs to verify the effect of metals in CO2 uptake isotherm. The salophen-based porous polymers were simply built by Schiff base chemistry under solvothermal condition, where 1,3,5-triformylphloroglucinol and p-phenylenediamine were utilized as building units for a two-dimensional layered structure. Metal coordination in salen and salophen-type ligands is well known in coordination chemistry, and herein, imine and hydroxyl groups in the S-COP structure play a role to incorporate metal ions. As a typical example, zinc-coordinated S-COPs (hereafter, S-COP-Zn) were synthesized via a facile post-modification, and S-COP-Zn shows double increase in CO2 adsorption capacity (3.23 mmol g-1) than bare S-COP (1.51 mmol g-1), measured at 273 K. We assume that the high CO2 uptake is attributed to the electrostatic field provided by metal ions as well as the strong interaction between CO2 and open metal sites. The combination of porous polymers with metal ions would provide a new idea in CCS technology to enhance gas uptake capacity of adsorbents.

Metal coordination in salophen-linked covalent organic polymers for enhanced CO<sub>2</sub> capture

248th National Meeting (2014)

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Metal coordination in salophen-linked covalent organic polymers for enhanced CO2 capture

Metal coordination in salophen-linked covalent organic polymers for enhanced CO₂ capture