Hydrothermal Synthesis of a Novel Double-Sided Nanobrush Co3O4 Catalyst and Its Catalytic Performance for Benzene Oxidation

A double-sided nanobrush Co3O4 (Co3O4-B) catalyst was successfully prepared by a hydrothermal method for the first time, and Co3O4 rods (Co3O4-R), Co3O4 hexagonal plates (Co3O4-H) and Co3O4 double-sided helianthus discs (Co3O4-D) were also synthesized through tuning the water/ethanol ratio. Among all of the as-prepared catalysts, the Co3O4-B catalyst exhibited the best catalytic activity for benzene oxidation. The excellent catalytic performance could be attributed to the surface abundance Co3+ species, good low-temperature reducibility and high number of lattice defects with substantial active oxygen species, which resulted from the unique structure of the double-sided nanobrush. The stability and water tolerance tests demonstrated that the Co3O4-B catalyst displays excellent stability for benzene combustion, and the deactivation caused by water vapor is also reversible. It is concluded that the unique structure of the catalysts plays a crucial role in determining its catalytic oxidation performance.