Symmetrical spiral forms of filamentous carbon formed from butadiene-1,3 on the Ni-Cu/MgO catalyst: Regularities and mechanism of growth

High resolution electron microscopy (HREM) was used to study the regulariti es of formation of symmetrical spiral forms of filamentous carbon from buta diene-1,3 on a Ni-Cu/MgO catalyst at 450 degrees C. Mirror-symmetrical carb on filaments coiled in spirals were shown to grow from one particle of the Ni-Cu alloy. A microphase of metastable carbide Ni3C was formed on the fron t side of the particle during filament growth, and the crystalline particle of the Ni-Cu alloy included a series of twinning planes (111) parallel to the min or symmetrical plane of the crystal that separated twin blocks with the fee structure. A mechanism of growth of the symmetrical spiral forms o f filamentous carbon is proposed.