Cobalt oxide-based catalysts supported on zirconia fibers synthesized by atomic layer deposition

LEONARDI, SABRINA A.; MILT, VIVIANA G.; FONTANINI, MARÍA M.; MIRÓ, EDUARDO E.; BORTOLOZZI, JUAN P.

MATERIALS CHEMISTRY AND PHYSICS

ELSEVIER SCIENCE SA

Año: 2023 vol. 294

0254-0584

This work is focused on the synthesis and evaluation of cobalt oxides grown onto zirconia fibers by the Atomic Layer Deposition (ALD) technique. CO oxidation is a wide studied reaction so that it was used as a model for testing the synthesized catalysts. Morphological and physicochemical properties were investigated through various characterization techniques. The deposited loading of the active phase was low (<1.2 at.% in all samples), and it was dispersed homogeneously along the zirconium oxide with fiber morphology with an length/diameter aspect ratio of about 50. Bulk and surface analysis showed the presence of different cobalt species (Co2+ and Co3+) that allow obtaining active catalysts for the reaction under study. Both the total amount of cobalt and the proportion of Co3+ species were higher as the number of ALD cycles increased. Through stability experiments, a change in the active species was detected after various cycles of reaction. This modification led to an increase in the surface Co3+ amount with changes in the coordination state.