Surface Tension Effects on the Reactivity of Metal Nanoparticles

Lin Li, Frank Abild-Pedersen, Jeff Greeley, Jens K. Nørskov*

*Corresponding author for this work

Research output: Contribution to journalLetterResearchpeer-review

Abstract

We present calculated adsorption energies of oxygen on gold and platinum clusters with up to 923 atoms (3 nm diameter) using density functional theory. We find that surface tension of the clusters induces a compression, which weakens the bonding of adsorbates compared with the bonding on extended surfaces. The effect is largest for close-packed surfaces and almost nonexistent on the more reactive steps and edges. The effect is largest at low coverage and decreases, even changing sign, at higher coverages where the strain changes from compressive to tensile. Quantum size effects also influence adsorption energies but only below a critical size of 1.5 nm for platinum and 2.5 nm for gold. We develop a model to describe the strain-induced size effects on adsorption energies, which is able to describe the influence of surface structure, adsorbate, metal, and coverage.

Original languageEnglish
JournalJournal of Physical Chemistry Letters
Volume6
Issue number19
Pages (from-to)3797-3801
Number of pages5
ISSN1948-7185
DOIs
Publication statusPublished - 2015
Externally publishedYes

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