Fabrication of Co3O4 nanospheres and their catalytic performances for toluene oxidation: The distinct effects of morphology and oxygen species

Abstract

Co3O4 shows great effective and active on account of its weaker Co–O bond and higher oxygen binding rate. Co3O4 catalysts with different morphologies exhibit great difference in catalytic activity, which is closely related to their surface element composition, oxygen species and predominantly exposed crystal facets. Morphology and facet control have been proved to be effective routes to vary catalytic performances of Co based catalysts. In this work, three self-assembled Co3O4 nanospheres with different morphologies were successfully prepared by solvothermal and hydrothermal methods with different cobalt precursors without using any template, and were employed to the complete catalytical combustion of toluene. The best catalyst, H sample achieved a toluene conversion of 90 % at approximately 248 °C, which was 50 °C lower than that of the P sample. The superior catalytic performance of the H sample could be attributed to its higher Co3+ content, more adsorbed oxygen species and highly active {110} facets. More importantly, the H sample showed a stable activity for toluene catalytic combustion during 100 h test and displayed a good water resistance property, showing a great potential for practical applications.