CO and ethanol oxidation over LaCoO3 planar model catalysts: Effect of the thickness

The catalytic performance of the LaCoO3 thin films toward CO and ethanol oxidation was studied in a reactor designed for the investigation of model planar catalysts. The effect of the thickness on the catalytic efficiency and the surface oxygen vacancies offers a straightforward method to identify or discriminate the oxygen species involved in the catalytic reaction. The weight-normalized reaction rate is demonstrated to be an intrinsic parameter and thus confirms the participation of the bulk lattice-oxygen in the studied catalytic reactions. Compared to other perovskite oxide powder catalysts, thin film catalysts show a remarkably higher activity toward ethanol and CO oxidation.

The weight-normalized rate over planar polycrystalline LaCoO3 catalysts with different thicknesses can be fitted with a single curve in the temperature range where the reactor can be considered as differential (conversion yield below 20%). This behavior hints at the involvement of the lattice oxygen in the catalytic oxidation of ethanol and CO.Figure optionsDownload as PowerPoint slideResearch highlights
► LaCoO3 films of different thicknesses were used in the oxidation of ethanol and CO.
► The involvement of the lattice oxygen in the catalytic reaction was demonstrated.
► Thin-film based catalysts exhibited higher intrinsic activity than their bulk counterpart.