Preparation of Mesoporous Silica by Nonionic Surfactant Micelle–Templated Gelation of Na2SiO3 and H2SiF6 and Application as a Catalyst Carrier for the Partial Oxidation of CH4

Abstract

Mesoporous silica (MSPN12) was prepared by nonionic surfactant micelle–templated gelation of sodium silicate (Na2SiO3) and fluorosilicic acid (H2SiF6) in aqueous solution, characterized by a range of instrumental techniques, and tested as a support for Ni and Rh catalysts in the partial oxidation of methane (POM). Calcined and sintered MSPN12 exhibited well-defined d00l-spacings (3.5–4.39 nm), narrow pore distributions (2.4–3.1 nm), and large specific surface areas (552–1,246 m2 g−1), and was found to be highly thermally stable. Microscopic imaging revealed that MSPN12 comprised spherical particles with a uniform diameter of ~0.7 µm, with each particle featuring firm and regular honeycomb-type pores. MSPN12-loaded Ni and Rh maintained stable POM activity at 700 °C during almost 100 h on stream, which were comparable to those for the commercial Rh(5)/Al2O3 catalyst in terms of methane conversion and H2 formation selectivity. Thus, the combination of structural stability and favorable physicochemical properties resulted in good POM performance.