Supported Cobalt Oxide Nanoparticles: The Influence of Mesoporous Materials and their Role in Methyl Phenyl Sulfide Oxidation Reactions

Abstract

The effect of the support in the incorporation of cobalt oxide nanoparticles on mesoporous materials (SBA-15) and mesoporous cellular foam (MCF) was investigated. The materials were characterized using various techniques. The XRD diffraction patterns showed that the porous structures remained after cobalt incorporation, while high-angle XRD of the MCF showed CoO peaks, in contrast to Co-SBA-15 which exhibited Co3O4. This was confirmed by XPS technique. The SEM-EDS and HRTEM-STEM microscopy indicate a distribution of cobalt oxides uniform in the samples synthesized and the average size of the particles is 1.88 nm. H2-TPR analysis highlighted the interaction between the support surfaces and the metal oxide (SMSI). It was observed that in the SBA-15 structure, small clusters of cobalt oxide formed with a strong interaction with silica, leading to high reduction temperatures. The catalysts activity was characterized in oxidation reactions of Methyl Phenyl Sulfide and a correlation was observed between the characterization results and the enhanced selectivity and yield towards sulfone exhibited by Co-MCF.