Thermo Catalytic decomposition of methane on Ni/SiO_2 catalyst into pure hydrogen and carbon nanotubes

摘要

Thermo-catalytic decomposition of methane is a promising approach to produce COx-free hydrogen and carbon nanotubes at a relatively low cost through a single-step process. Ni catalysts supported on silica as textural promoter prepared by wet impregnation and co-precipitation methods are studied to produce pure hydrogen and carbon nanofibers in a fixed-bed quartz reactor at 700 ?and at atmospheric pressure. The loading amounts of Ni in the Ni/SiO_2 catalyst were changed from 30 to 70 wt%. The catalytic activity is mainly influenced by the amount of metal loading, catalyst preparation method, reaction temperature and type of support material. It was observed that the catalytic activity and the yields of hydrogen and carbon nanofibers depended strongly on the loading amount of Ni and preparation method. 50% Ni/SiO_2 catalyst prepared by wet impregnation method found more suitable in terms of higher methane conversion and hydrogen yield compare to other catalyst.