Atomic scale insights into ethanol oxidation on Pt, Pd and Au metallic nanofilms: A DFT with van der Waals interactions

In this work, we use dispersion corrected DFT calculations (DFT + D3) to explore the ethanol decomposition on Pt, Pd and Au metallic nanofilms. The structural and energetic properties of ethanol and the most common intermediate products in ethanol oxidation were investigated, namely acetaldehyde, acetic acid, acetyl and CO. Our results suggests that even when starting from an initial condition very close to the equilibrium geometry it is not possible to obtain the correct adsorption properties from standard DFT calculations; the system is trapped in a local minimum geometry and the correct adsorption geometry cannot be accessed. Therefore, the inclusion of vdW interactions is fundamental to assure correct adsorption properties and agreement with experimental data. By analyzing the adsorption of ethanol and its oxidation products on metallic nanofilms we found that Pt (1 1 1), Pt/Pd (1 1 1), Pt/Au (1 1 1) and Pd/Pt (1 1 1) nanofilms present enhanced adsorption properties and seem to be good candidates for ethanol catalysis. (C) 2013 Elsevier B.V. All rights reserved.