CO2 adsorption and separation on phloroglucinol-melamine -formaldehyde polymeric nanofibers

Phloroglucinol-melamine-formaldehyde polymeric nanofibers (PMF) were hydrothermally synthesized by a polycondensation method using melamine, phloroglucinol and formaldehyde as starting materials. The effect of temperature on the PMF synthesis was investigated. The morphology and structure of the as-synthesized PMF were characterized by the scanning electron microscope (SEM), transmission electron microscope (TEM), N2 adsorption-desorption and Fourier-transform infrared spectrometer (FT-IR) etc. Pure gas adsorption equilibrium isotherms of CO2 and N2 were determined by the volumetric method. The PMF sample synthesized at 393 K presented a higher specific surface area (64 m2/g) and a higher adsorption capacity of CO2 (1.83 mmol/g @ 118 kPa, 298 K). Breakthrough column experiments indicated that efficient separation of CO2-N2 mixtures could be achieved on the PMF at 298 K and various pressures ranging from 200 to 600 kPa. After the PMF was thermally treated at 873 K in various atmospheres such as N2, H2, water vapor, etc., it was found that the specific surface area and micropore volume were greatly increased. Among the posttreated PMF samples, the one treated in 15% H2O stream showed an improved CO2 adsorption amount up to 2.83 mmol/g at 298 K and 118 kPa. © 2019, Science Press. All right reserved.