Morphology-dependent performance of Co3O4 via facile and controllable synthesis for methane combustion

•Co3O4 with different morphologies were controllably synthesized.•Morphology/plane-dependent performance of Co3O4 for methane combustion was studied.•The relationship between the morphology and redox property was studied.•{111} surface planes of Co3O4 were more reactive than {100} surface planes.

Spinel type cobalt oxide (Co3O4) nanocrystals were controllably synthesized with different morphologies (cubical, hexagonal and flower-like) via a facile hydrothermal method. The properties of the nanostructured Co3O4 were characterized by XRD, SEM, TEM, HRTEM and XPS techniques. The performance of the catalysts in methane combustion was evaluated under lean methane atmosphere. Superior catalytic activities for methane combustion were observed over these oxides. The performances seemed to depend on their morphologies. The catalytic activities of flower-like Co3O4 and hexagonal plate-like Co3O4 were comparable to those of noble metal catalysts due to the preferred exposure of more active {111} crystal plane. In case of cubical Co3O4 the {001} plane is the dominantly exposed crystal plane. The results may provide significant insights for the development of nanostructured metal oxide catalysts for the catalytic combustion of methane.

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