Platinum nanoparticles on Al2O3: Correlation between the particle size and activity in total methane oxidation

Catalytic activity of the size-controlled platinum nanoparticles supported on the acid-pretreated γ-alumina has been tested in complete methane oxidation under lean conditions. The mean sizes of platinum particles varied from 1.3 to 10 nm with the narrow size distribution (TEM data). It has been found that the reaction under study is strongly size sensitive. The size dependence of the specific catalytic activity is narrow and bell-shaped, with the maximum TOF value observed for the catalysts containing partially oxidized platinum with the mean particle sizes of about 2 nm. The observed strong size sensitivity is shown to originate from the size dependence of the apparent activation energy of the methane oxidation and/or the platinum oxidation state in the catalytically active nanoparticles.

Graphical abstractCatalytic activity of size-controlled platinum nanoparticles supported on the acid-pretreated γ-alumina has been measured in complete methane oxidation under lean conditions. The strong size sensitivity was shown to originate from the size dependence of the apparent activation energy of the methane oxidation and/or oxidation state of platinum in the catalytically active nanoparticles.Figure optionsDownload full-size imageDownload high-quality image (49 K)Download as PowerPoint slide