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

초록

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 d(001)-spacings (3.5-4.39 nm), narrow pore distributions (2.4-3.1nm), and large specific surface areas (552-1,246 m(2) g(-1)), and was found to be highly thermally stable. Microscopic imaging revealed that MSPN12 comprised spherical particles with a uniform diameter of similar to 0.7 mu m, with each particle featuring firm and regular honeycomb-type pores. MSPN12-loaded Ni and Rh maintained stable POM activity at 700 degrees 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 H-2 formation selectivity. Thus, the combination of structural stability and favorable physicochemical properties resulted in good POM performance.

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