Characterization of porous texture in composite adsorbents based on exfoliated graphite and polyfurfuryl alcohol

Composite activated carbon monoliths were prepared from polyfurfuryl alcohol-impregnated compressed expanded graphite (CEG) blocks by pyrolysis at 923 K followed by steam activation at 1073 K. The porous texture of these materials was analysed from physical adsorption measurements of N2 at 77 K and CO2 at 273 K. Pyrolysis gives rise to a nitrogen surface area higher than for many conventional carbonised precursors of active carbons. Activation develops even more the porosity. At low burn-offs, there is principally creation of new pores (including ultramicropores). At higher burn-offs (of the order of 40%), opening of preexisting pores takes place. The materials obtained are essentially microporous and exhibit a rather narrow pore size distribution.