Ligand-protected precipitation of cobalt supported on silica nanospheres for catalytic oxidation of toluene

Abstract

Cobalt-based materials have been considered efficient catalysts for the oxidative degradation of VOCs. However, the bulky and uneven particles strongly restrict the catalyst activity and stability. To address these challenges, 30 nm SiO₂ nanospheres are employed as a functional support for efficient loading of cobalt active species. One-pot synthesis is performed through evaporation-induced precipitation of ethylenediamine-coordinated cobalt precursors and monodisperse silica colloids, resulting in the uniform dispersion of ultrasmall Co₃O₄ particles on SiO₂ nanospheres. In toluene oxidation, the optimal sample loaded with 10% cobalt (10Co/SiO₂_LP) exhibits superior catalytic performance demonstrated by a low T₉₀ of 235 °C, excellent long-term stability and good vapor resistance compared with the contrast sample (10Co/SiO₂_IM) synthesized through the incipient impregnation method (10Co/SiO₂_IM) as well as similar reported cobalt-based catalysts. It is expected that the demonstrated work will provide a straightforward method for preparing high-performance non-noble metal catalysts applicable to the oxidative degradation of VOCs.