Steady and efficient decomposition of methane can be achieved at 625-675 degreesC over copper-promoted (8-15 wt.% of copper) nickel catalysts prepared from a Feitknecht compound precursor. Such catalysts permit one to increase the yield of catalytic filamentous carbon (CFC) and control both microstructural and textural properties of CFC by varying the copper concentration in the catalyst. The maximal conversion of methane into hydrogen and carbon reaches 40% at 675 degreesC at the carbon capacity not lower than 700 g/g(Ni) under optimal conditions. The BET surface area of the CFC is 285.9 m(2)/g. The influence of promotion of nickel-containing catalysts with copper on the catalytic activity is discussed. (C) 2003 Elsevier Science B.V. All rights reserved.