Phloroglucinol based microporous polymeric organic frameworks with-OH functional groups and high CO₂ capture capacity

A new family of microporous polymeric organic frameworks (POF)s is described. The POFs are assembled from phlorglucinol (1,3,5-trihydroxybenzene) and several benzaldehyde derivatives under solvothermal conditions using Bakelite type chemistry of forming C-C bonds without any catalyst. The materials exhibit semiconductor-like optical absorption properties with energy gaps in the range of 1.5-2.5 eV. The new materials form as uniform, microporous, spherical particles and exhibit surface areas up to 917 m² g ^-1. The micropores have a very uniform size as the gas adsorption isotherms of these amorphous materials are similar to those of crystalline microporous zeolites. The micropores are internally decorated with a large number of -OH reactive groups which are available for functionalization. The POFs capture as much as 18% of their mass of CO₂ at atmospheric pressure which is significantly larger than other porous polymers including systems which exhibit much larger surface areas; sodium-functionalized POFs exhibit enhanced heat of adsorption for H₂ of 9 kJ/mol compared to pristine POF at 8.3 kJ/mol.