Sub-ambient CO oxidation over mesoporous Co3O4: Effect of morphology on its reduction behavior and catalytic performance

The influence of the Co3O4 morphology on its redox behavior and catalytic performance in the CO oxidation reaction is studied. Three different Co3O4 morphologies were synthesized by precipitation and hydrothermal methods. TEM and SEM observations clearly show the different obtained morphologies: rods, wires and a mixture of plates and cubes. The textural properties depend on the morphology and the redox ones on the particle size. XRD analysis reveals a spinel structure in all solids with a preferential exposition of the [1 1 0] plane in the Co3O4 rods sample. This preferential exposition, along with its higher specific surface area provides the rods with more efficient oxygen storage capacity resulting in an excellent catalytic performance compared to the other two morphologies.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (90 K)Download as PowerPoint slideHighlights► 3 different Co3O4 morphologies were synthesized by precipitation and hydrothermal methods. ► The reduction behavior under H2 flow is strictly correlated to the particle size. ► DRX analysis reveals a preferential exposition of the [1 1 0] plane in the Co3O4 rods. ► The reduction profile under CO, the OSC and catalytic activity depend on the plane exposition.