1998 Volume 1998 Issue 181 Pages 8-13
Mesoporous carbons were prepared by steam activation of the mixture of a brown coal (Morwell) and metal (Fe, Ni or Co) acetylacetonate complexes (metal, 2.5 wt% of coal). According to the analysis with the N2 adsorptionisotherms measured at 77K, enhancement of mesoporosity in the activated carbons clearly depends upon the type ofmetals, i.e., Fe>Co>Ni. X-ray diffraction patterns showed the presence of metal oxide with less-crystalline carbon. Observation with transmission electron microscope (TEM) clearly illustrated wide dispersion of nano-scale (5-10nm∅) particles of the metal oxide and mesoporous pits as mesopores in the disordered carbon microtexture. Suchcharacteristic mesopores were not found in the samples prepared only from the coal, and therefore can be recognizedas characteristic mesopores induced by metal complex. The properties in size distribution and dispersion mode for metaloxide particles were investigated with TEM photographs, and found to be characteristic for each type of metals. Theseproperties were also discussed in connection with the morphological feature of mesoporous texture. The results canbe used to control not only the amount of mesopore but also the morphology of the mesoporous texture.
