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 language | English |
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Article number | 084703 |
Journal | Journal of Chemical Physics |
Volume | 145 |
Issue number | 8 |
DOIs | |
Publication status | Published - 2016 Aug 28 |
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry