Effect of Surface Modification on the Changes of Pore Structure ,Surface Property,and CH4Adsirptiv of Activated Carbon Fibers

摘要

Pitch-based activated carbon fibers previously oxidized in air at various temperatures were modified bymagnesium oxide/hydroxide deposits and their changes of pore structure,surface property,and methane adsorptivity due to surface modification were examined by low temperature N2 adsorption,thermal desorption analysis,DRIFT,polar molecule adsorption,and high pressure adsorption.It was found that deposit of magnesium oxide/hydroxide increases the micropore volume of ACFs oxidized below 673 K while decreases those of ACFs oxidized above 773 K.DRIFT and titration results indicate that magnesium species are mainly supported on the carboxyl groups of ACFs' surface.The high-pressure methane adsorption amount does not increase with the increase of magnesium amount while changes with the magnesium deposit and geometric structure of ACFs.