Effective catalysts for direct cracking of methane to produce hydrogen and filamentous carbon Part I. Nickel catalysts

Data obtained by studying model catalytic systems were used to develop high-loaded nickel catalysts for direct cracking of methane into hydrogen and catalytic filamentous carbon (CFC). The approach to the synthesis of these catalysts can be the basis for development of catalytic nickel systems for commercial processing of natural gas. The catalysts were synthesized by fusing nickel nitrate with zirconium nitrate, or nickel nitrate with copper-doped aluminium nitrate followed by decomposition of the mixture at 300-450 degrees C and its additional stabilization by silica. The silica textural promoter was formed by thermal decomposition of polyethoxysilane introduced into pores of the oxide matrix. The catalysts reduced by hydrogen comprised nickel in the amount of 85-90%. Unlike preparation of co-precipitated systems, synthesis of the catalysts mentioned does not include stages of filtration and wastewater treatment. Principal characteristic of the catalysts' effectiveness for the reaction of decomposition of methane, i.e. carbon yield per gram of nickel, of the suggested systems was close or superior to that achieved before using the best nickel or nickel-copper catalysts prepared by co-precipitation. (C) 2000 Elsevier Science B.V. All rights reserved.