Development of methods of growing carbon nanofibers on silica glass fiber supports

Samples of carbon nanofibers (CNF) with different carbon contents (6.5–55 wt.%) are prepared by decomposition of CH4 on Ni catalysts supported on silica glass fibers (SGF). The incipient wetness impregnation of support, introduction of the active component into alumina washcoat and ion-exchange methods were used to prepare Ni catalysts on SGF. On the optimal catalyst prepared on washcoated SGF, carbon forms as CNF of diameter 20–50 nm, and the carbon capacity is rather high—55 gC/gNi. Diameter of the CNF corresponds to the size of catalyst particles of Ni metal, which have the cuboctahedral form typical for the formation of CNF with conical embedding of graphite layers with respect to the filament axis. The SGF with supported CNF is a mesoporous material with polydisperse pore distribution similar by structural and textural parameters to the granulated bulk CNF obtained in methane decomposition over high-loaded nickel-alumina catalysts. The XRD, ESR and DTA methods were used for phase and structural analysis and demonstrated that CNF has a uniform graphite-like structure and does not include the amorphous phase.