A New Low-Cost Mesoporous Silica as a Promising Support of Ni-Catalysts for High-Hydrogen Generation via Dry Reforming of Methane

In this study, a new low-cost mesoporous silica produced from natural resources was used as promising support of Ni-active phase catalysts for hydrogen production. The Ni
²
+-catalysts were synthesized by wet chemical impregnation and tested in the dry reforming of methane (DRM) at atmospheric pressure, between 550 and 750°C. The fresh and spent catalysts were characterized by XRD, TEM and TG/DTA techniques. The catalytic study revealed that all Ni
²⁺
-catalysts were selective for hydrogen production and exhibited a long-term stability with high conversion of methane exceeding 90% at 750°C. This result was correlated with the presence of Ni nanoparticles dispersed homogeneously on the mesoporous silica surface due to metal-support interactions and which were formed under the effect of reducing reaction mixture, as evidenced by XRD and TEM observations. Concomitantly, the presence of graphitic carbon structures was increasingly observed during the catalytic process with the high value of 14% found on Ni(20 wt.%)/mes-silica. Their growth seems to be limited compared with many homologous silica, prepared differently. No significance deactivation was recorded after 24 hours of the DRM reaction (<;2%), meaning that the textural properties of the Ni nanoparticles were not changed by the presence of the carbon nanotubes. The low cost mesoporous silica prepared herein presents a high catalytic performance towards DRM, better to that obtained on other existing silica supports.