THE FORMATION OF MORPHOLOGICAL STRUCTURES OF CARBON FROM HYDROCARBONSON NICKEL-CONTAINING CATALYSTS

The regularities of the formation of various morphological structures of carbon from methane, n-hexane, and 1,3-butadiene on Ni, Ni/MgO, and Ni-Cu/MgO catalysts are studied by electron microscopy and X-ray anal ysis. The structures of filamentary carbon on nickel and nickel-copper alloys are substantially different. In the case of nickel, carbon fil aments are formed by coaxial cylinder- or funnel-shaped (002) graphite layers, with the symmetry axis coinciding with the direction of the c arbon growth. Carbon filaments formed on the nickel-copper alloy consi st of parallel (002) graphite planes oriented perpendicularly to the f ilament axis. Assumptions on the mechanism of the filament growth are considered.