Fractal analysis of pre-reduced Pt/TiO2 catalysts for formaldehyde oxidation

Abstract

The amount of reactive sites, usually dispersed noble atoms, on the top of a catalyst rough surface is characterized within the framework of fractal geometry. The surface fractal dimension d_fs was calculated from their nitrogen adsorption isotherms using an A. V. Neimark model. It was found that the catalysts pre-reduced at different temperatures showed different d_fs values and distinct formaldehyde oxidation performance. As expected, a good agreement between performance and d_fs values was achieved. These results are significant for our understanding of the nature of the catalyst's surface roughness and illustrate the importance of considering difference in surface fractal geometry in analyzing catalytic behavior.