(209d) Hydrogen production by enhanced methane decomposition over Co-Rh bimetallic catalyst

The performance of Co-Rh/TiO₂ catalyst were studied via methane decomposition reaction to produce hydrogen and carbon nanotubes. The TiO₂ supports were synthesized by an improved EISA approach and Co-Rh nanoparticles over as-synthesized TiO₂ supports were obtained using co-impregnation method. The fresh and examined catalysts were characterized by BET, TGA, XRD, SEM, and TEM. The findings showed that texture of TiO₂ support has a significant effect on catalytic performance. The superior catalytic activity and stability were exhibited by the catalyst synthesized with TiO₂ at 600 ^oC due to better metal dispersion and higher anatase phase content in the support. It was also observed that initial activity relies on the specific surface area and the hydrogen productivity for equal activation level was very well related to the anatase composition of produced catalyst. The phase composition of TiO₂ contributed to the varied nature of deposited carbon. It was also revealed through SEM and TEM images that anatase TiO₂ produced smaller multi-walled carbon nanotubes (MWCNTs) with a more compatible diameter distribution. The apparent activation energies for different Co-Rh catalysts changed between 60-100 kJ/mol. The catalyst with an amorphous composition increases the formation of CHx carbon species.