Nanocasting synthesis of mesostructured Co 3O 4 via a supercritical CO 2 deposition method and the catalytic performance for CO oxidation

Abstract

We demonstrate a supercritical CO 2 (scCO 2) deposition method to synthesize mesostructured Co 3O 4 with crystalline walls using SBA-15 as the hard template. By variation of the scCO 2 pressure, randomly organized nanorods or a highly ordered mesoporous structure of Co 3O 4 is obtained after only one filling operation. The catalytic tests show that the randomly organized Co 3O 4 nanorods display excellent activity for CO oxidation with the complete conversion of CO even at room temperature, while neither the ordered mesoporous nor bulk Co 3O 4 is active at this low-temperature, demonstrating the important role of Co 3O 4 morphology in catalysis. Graphical Abstract: [Figure not available: see fulltext.] © 2011 Springer Science+Business Media, LLC.