Porous Silica Particles Modified in a NH3 + H2O + H2O2 Mixture: Structure, Filling with Cobalt Oxide, and Catalytic Activity for CO Conversion

Silica particles containing large mesopores (5–25 nm in size) and micropores (0.6–2 nm in size) have been prepared by chemical etching of spherical micro- and mesoporous silica particles in an ammonia + water + hydrogen peroxide mixture. The specific surface area and pore volume of the particles are 510 m2/g and 0.8 cm3/g, respectively. Using capillary impregnation, we have synthesized Co3O4 (2–4 wt %) in pores of the particles. The composition and structure of the resultant materials have been studied. The Co3O4/SiO2 composite particles have been shown to be stable and exhibit catalytic activity for the CO oxidation process.