Investigation of ZnCo₂O₄-Pt hybrids with different morphologies towards catalytic CO oxidation

In this work, three kinds of ZnCo₂O₄ morphologies, that is, rod, plate and sphere, have been successfully prepared and further used to support Pt nanoparticles (NPs) via in situ deposition. The as-prepared ZnCo₂O₄-Pt hybrid nanomaterials were then carefully characterized by SEM, TEM, XRD, XPS, ICP EDX, and N₂ adsorption measurement in great detail. Besides, the three catalysts were also evaluated by the model reaction of catalytic CO oxidation. After comparing the difference in the three kinds of morphologies, we have tried to clarify the reason for their different catalytic performances. As a result, the ZnCo₂O₄-Pt sphere was found to be the most active, attaining 100% CO conversion at a relatively low temperature of 140 °C, because more Pt NPs are prone to distribution on the surface of ZnCo₂O₄ spheres than the other ones. The following cycling tests confirm the excellent stability of the as-prepared ZnCo₂O₄-Pt samples.