Selective and enhanced CO2 adsorption on fluorinated activated carbon fibers

Pitch-based activated carbon fibers (ACFs) were fluorinated in temperatures from 298 to 473 K using diluted fluorine gas. The N-2 adsorption and desorption isotherms at 77 K for the ACFs fluorinated at 298 K (F298) showed a decrease in the amount of adsorbed N-2 mainly because of diffusional problems of the N-2 molecule. Enhanced CO2 adsorption was also observed on the F298. The CO2 absorptivity for the F298 is probably caused by the development of microporosity and enhanced interactions between the weakened C-F bonds and CO2 molecules.