Surface morphology, metal dispersion, and pore texture of transition metal-doped monolithic carbon aerogels and steam-activated derivatives

Fe, Co, Ni and Cu-doped organic aerogels were prepared by sol-gel method from resorcinol-formaldehyde mixtures containing the corresponding metal acetates. They were carbonized Under nitrogen flow at 1000degreesC, and some of them were further steam activated at 900degreesC. A blank sample was also prepared. During carbonization. the shape of the CH4 and CO2 evolution profiles depended oil the nature of the metal present in the aerogel. Samples were characterized by scanning electron microscopy, high resolution transmission electron microscopy, and X-ray diffraction. Surface area and pore texture were characterized by N-2 and CO2 adsorption at -196 and 0degreesC, respectively, and by mercury porosimetry. Surface morphology of the monolithic organic aerogels was similar to that of their corresponding, parent organic aerogels but with smaller particle size. Metals were dispersed at nanometric scale and some of them partially graphitized the carbon Structure. The effects of carbonization and steam activation oil the surface area and porosity varied according to the nature of the metal present. (C) 2004 Elsevier Inc. All rights reserved.