Active sites of ligand-protected Au{sub 25} nanoparticle catalysts for CO{sub 2} electroreduction to CO
- National Energy Technology Laboratory, U. S. Department of Energy, Pittsburgh, Pennsylvania 15236 (United States)
Recent experimental studies have reported the electrochemical reduction of carbon dioxide (CO{sub 2}) into CO at atomically precise negatively charged Au{sub 25}{sup −} nanoclusters. The studies showed CO{sub 2} conversion at remarkably low overpotentials, but the exact mechanisms and nature of the active sites remain unclear. We used first-principles density functional theory and continuum solvation models to examine the role of the cluster during electrochemical CO{sub 2} reduction and analyze the free energies of proposed intermediate species. Contrary to previous assumptions, our results show that the fully ligand protected cluster is not an active CO{sub 2} reduction catalyst because formation of the crucial carboxyl intermediate required very high electrochemical potentials. Instead, our calculations suggest that the reduction process likely occurs on a dethiolated gold site, and adsorbed carboxyl intermediate formation was significantly stabilized at dethiolated gold sites. These findings point to the crucial role of exposed metal sites during electrochemical CO{sub 2} reduction at gold nanocluster catalysts.
- OSTI ID:
- 22657997
- Journal Information:
- Journal of Chemical Physics, Vol. 144, Issue 18; Other Information: (c) 2016 U.S. Government; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-9606
- Country of Publication:
- United States
- Language:
- English
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