Twinning in fcc lattice creates low-coordinated catalytically active sites in porous gold

Marian Krajčí, Satoshi Kameoka, An Pang Tsai

    Research output: Contribution to journalArticlepeer-review

    10 Citations (Scopus)

    Abstract

    We describe a new mechanism for creation of catalytically active sites in porous gold. Samples of porous gold prepared by de-alloying Al2Au exhibit a clear correlation between the catalytic reactivity towards CO oxidation and structural defects in the fcc lattice of Au. We have found that on the stepped {211} surfaces quite common twin boundary defects in the bulk structure of porous gold can form long close-packed rows of atoms with the coordination number CN = 6. DFT calculations confirm that on these low-coordinated Au sites dioxygen chemisorbs and CO oxidation can proceed via the Langmuir-Hinshelwood mechanism with the activation energy of 37 kJ/mol or via the CO-OO intermediate with the energy barrier of 19 kJ/mol. The existence of the twins in porous gold is stabilized by the surface energy.

    Original languageEnglish
    Article number084703
    JournalJournal of Chemical Physics
    Volume145
    Issue number8
    DOIs
    Publication statusPublished - 2016 Aug 28

    ASJC Scopus subject areas

    • Physics and Astronomy(all)
    • Physical and Theoretical Chemistry

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