Objectives
Activated carbon supporting particles of metallic compound is expected for catalytic use in many industrial and environmental fields. We have already reported about the preparation of mesoporous (2<D<50nm) activated carbons with metal oxide nanoparticles. Coal and organometallics are used as starting materials in this method. As a next step, we aim to evaluate the dependence of texture in the activated carbons prepared by this method upon types of organometallics.
Results
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) at 1173K. According to the analysis with the N2 adsorption isotherms measured at 77K, enhancement of mesoporosity in the activated carbons clearly depends upon the type of metals (Table 1). 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 (5-10nmf) particles of the metal oxide and mesoporous pits as mesopores in the disordered carbon microtexture (Fig.1). Such characteristic mesopores were not found in the samples prepared from the coal without addition of the metal, and therefore can be recognized as characteristic mesopores induced by metal complex. The properties in size distribution and dispersion mode for metal oxide particles were investigated with TEM photographs, and found to be characteristic for each type of metals. These properties were also discussed in connection with the morphological features of mesoporous texture. The results can be used to control not only the amount of mesopore but also the morphology of the mesoporous texture.
Selected Publications
| 1) | Dispersion Properties of Metal Oxide Nanoparticles Supported in Mesoporous Activated Carbons, Tanso 1998 [No.181] 8-13, 1998 |
