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Updated: Mar 15, 2026
Synthesis and Catalytic Performance of Gold Intercalated in the Walls of Mesoporous Silica
Published on: July 9, 2015
Twinning in fcc lattice creates low-coordinated catalytically active sites in porous gold
Marian Krajčí1, Satoshi Kameoka2, An-Pang Tsai2
1Institute of Physics, Slovak Academy of Sciences, Dúbravská cesta 9, SK-84511 Bratislava, Slovak Republic.
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.
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