STUDY OF CARBON MOLECULAR-SIEVE FIBERS BY ATMOSPHERIC TPD-MS OF H2O, CO AND CO2

High-resolution temperature-programmed desorption mass spectrometry (T PD-MS) with a supersonic molecular beams (SMB) inlet system enables us to analyse quantitatively CO, CO2 and water from various sites on car bon molecular sieve fibres (CMSF). Three water sites up to 350 degrees C are observed. The first main water site is from desorption of physi cally adsorbed water molecules on the surface oxides and inside the mi cropores. The other two sites result from dehydration and decompositio n of surface oxides. The effects of relative humidity, oxide concentra tion and pore structure on adsorption of water on CMSF are studied. Gr adual oxide group decomposition at low temperature, up to 250 degrees C, is monitored and the kinetics of surface oxide formation in air at room temperature is studied.