A Comprehensive Search for Stable Pt-Pd Nanoalloy Configurations and Their Use as Tunable Catalysts

TitleA Comprehensive Search for Stable Pt-Pd Nanoalloy Configurations and Their Use as Tunable Catalysts
Publication TypeJournal Article
Year of Publication2012
AuthorsTan TL, Wang LL, Johnson DD, Bai KW
Journal TitleNano Letters
Volume12
Pages4875-4880
Date Published09
Type of ArticleArticle
ISBN Number1530-6984
Accession NumberWOS:000308576000076
Keywordsbimetallic clusters, bulk alloys, catalysis, cluster expansion, exchange current, first-principles, hydrogen adsorption, hydrogen evolution, hydrogen evolution reaction, j.-electrochem.-soc., laser vaporization, metal, moments developments, nanoalloy, nanoparticles, PD, Pt, total-energy calculations, wave basis-set
Abstract

Using density-functional theory, we predict stable alloy configurations (ground states) for a 1 nm Pt-Pd cuboctahedral nanoparticle across the entire composition range and demonstrate their use as tunable alloy catalysts via hydrogen-adsorption studies. Unlike previous works, we use simulated annealing with a cluster expansion Hamiltonian to perform a rapid and comprehensive search that encompasses both high and low-symmetry configurations. The ground states show Pt(core)-Pd(shell) type configurations across all compositions but with specific Pd patterns. For catalysis studies at room temperatures, the ground states are more realistic structural models than the commonly assumed random alloy configurations. Using the ground states, we reveal that the hydrogen adsorption energy increases (decreases) monotonically with at. % Pt for the {111} hollow ({100} bridge) adsorption site. Such trends are useful for designing tunable Pd-Pt nanocatalysts for the hydrogen evolution reaction.

URL<Go to ISI>://WOS:000308576000076
DOI10.1021/nl302405k
Alternate JournalNano Lett.