STRUCTURAL STUDIES OF ACTIVE-CARBON USED IN THE GROWTH OF SILICON-CARBIDE CATALYST SUPPORT

The microstructure of active carbon used in the growth of a silicon ca rbide catalyst support has been studied by BET area measurements, elec tron diffraction and high-resolution electron microscopy. The microstr ucture of the active carbon is consistent with different distributions of basic structural units (BSUs). These BSUs increase in size under h eat treatment by forming adjacent distorted columns. Ordering processe s are discussed from geometrical considerations based on reciprocal pa tterns. The reactivity of the interface between the active carbon and SiO vapour is controlled by the proportion of the highly reactive site s in the active carbon surface structure.