Peculiarities of filamentous carbon formation in methane decomposition on Ni-containing catalysts

Experimental data on the effect of CH4+H-2 mixtures composition and temperature on catalytic filamentous carbon (CFC) formation in methane decomposition on Ni-containing catalyst are presented. Microscopy studies have shown that at the lowest methane concentration (2.5%) the amount of CFC produced per unit of catalyst mass is limited primarily by the surface effects imposed by the carbon growth centers (GC) rather than by volume ones. The shape of GC where carbon filament forms depends on the reaction medium composition and temperature. By varying the H-2 concentration in the reaction medium, one can change the texture of the CFC produced. (C) 1997 Elsevier Science Ltd.