| Autor: |
Friebel D; Joint Center for Artificial Photosynthesis, Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Mail Stop 976, Berkeley, California 94720, United States., Louie MW, Bajdich M, Sanwald KE, Cai Y, Wise AM, Cheng MJ, Sokaras D, Weng TC, Alonso-Mori R, Davis RC, Bargar JR, Nørskov JK, Nilsson A, Bell AT |
| Jazyk: |
angličtina |
| Zdroj: |
Journal of the American Chemical Society [J Am Chem Soc] 2015 Jan 28; Vol. 137 (3), pp. 1305-13. Date of Electronic Publication: 2015 Jan 16. |
| DOI: |
10.1021/ja511559d |
| Abstrakt: |
Highly active catalysts for the oxygen evolution reaction (OER) are required for the development of photoelectrochemical devices that generate hydrogen efficiently from water using solar energy. Here, we identify the origin of a 500-fold OER activity enhancement that can be achieved with mixed (Ni,Fe)oxyhydroxides (Ni(1-x)Fe(x)OOH) over their pure Ni and Fe parent compounds, resulting in one of the most active currently known OER catalysts in alkaline electrolyte. Operando X-ray absorption spectroscopy (XAS) using high energy resolution fluorescence detection (HERFD) reveals that Fe(3+) in Ni(1-x)Fe(x)OOH occupies octahedral sites with unusually short Fe-O bond distances, induced by edge-sharing with surrounding [NiO6] octahedra. Using computational methods, we establish that this structural motif results in near optimal adsorption energies of OER intermediates and low overpotentials at Fe sites. By contrast, Ni sites in Ni(1-x)Fe(x)OOH are not active sites for the oxidation of water. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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