Tuning the catalytic activity of Au-Pd nanoalloys in CO oxidation via composition

TitleTuning the catalytic activity of Au-Pd nanoalloys in CO oxidation via composition
Publication TypeJournal Article
Year of Publication2014
AuthorsCheng, D, Xu, H, Fortunelli, A
JournalJournal of Catalysis
ISSN00219517 (ISSN)
KeywordsAdsorption, Au-Pd nanoalloys, Calculations, Carbon dioxide, Catalyst activity, CO oxidation, Density functional theory, Design for testability, DFT calculation, First principles density functional theory (DFT) c, Icosahedral structure, Nano-alloys, Oxidation, Reaction energy barriers, Reaction mechanism, Reaction mechanisms, Structure (composition), Symmetric structures

Using a combination of analytic-potential and first-principles density functional theory (DFT) calculations, composition effects on energetics, adsorption energies, and catalytic activity of Au-Pd nanoalloys are investigated, selecting CO oxidation to CO2 as a prototypical reaction and 55-atom Au-Pd clusters with Mackay icosahedral structure as template systems. It is first shown that the Au54Pd1, Au43Pd12, Au42Pd13, and Au 12Pd43 nanoalloys with highly symmetric structures are well separated from other nanoalloys due to their special relative stability at the empirical potential and/or DFT levels, with CO adsorption energies on top of Au atoms found to be weakly dependent on composition in a range around 50:50 Au:Pd ratio. The explicit calculation of reaction energy barriers for the CO oxidation process then shows that these are sensitive to the composition of nanoalloys, where Au-rich clusters possess a high catalytic activity and the Au43Pd12 cluster is predicted to have the highest catalytic activ