Preparation and characterization of a highly dispersed and stable Ni catalyst with a microporous nanosilica support

Abstract

A microporous Stöber silica was synthesized by controlling the post-drying conditions. Using the silica as a support, a highly dispersed Ni catalyst was successfully prepared by a simple impregnation method. During the impregnation process, the Ni²⁺ cations could access the micropores of the support and they were turned into monodispersed Ni nanoparticles (<3 nm) after reduction. XRD, TEM, H₂-TPR and XPS results revealed that the micropores within the Stöber silica play an important role in the preparation of such a highly dispersed Ni catalyst. The as-prepared Ni/SiO₂ catalyst showed high catalytic performance and long-term stability for the partial oxidation of methane (POM) to synthesis gas, even at a very low metal loading (1.5 wt%). Such a low metal loading, which is not favorable to the carbon deposition, has been seldom reported so far for Ni- and Co-based catalysts for the POM reaction. More importantly, this strategy provides a simple and low cost method for further designing other silica-supported metal catalysts with high dispersion and anti-sintering ability.