In Situ Formation of an Oxygen-Evolving Catalyst in Neutral Water Containing Phosphate and Co 2+

American Association for the Advancement of Science (AAAS) - Tập 321 Số 5892 - Trang 1072-1075 - 2008
Matthew W. Kanan1, Daniel G. Nocera1
1Department of Chemistry, 6-335, Massachusetts Institute of Technology, Cambridge, MA 02139–4307, USA.

Tóm tắt

The utilization of solar energy on a large scale requires its storage. In natural photosynthesis, energy from sunlight is used to rearrange the bonds of water to oxygen and hydrogen equivalents. The realization of artificial systems that perform “water splitting” requires catalysts that produce oxygen from water without the need for excessive driving potentials. Here we report such a catalyst that forms upon the oxidative polarization of an inert indium tin oxide electrode in phosphate-buffered water containing cobalt (II) ions. A variety of analytical techniques indicates the presence of phosphate in an approximate 1:2 ratio with cobalt in this material. The pH dependence of the catalytic activity also implicates the hydrogen phosphate ion as the proton acceptor in the oxygen-producing reaction. This catalyst not only forms in situ from earth-abundant materials but also operates in neutral water under ambient conditions.

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This work was supported by a grant from the NSF Chemical Bonding Center (CHE-0802907). M.W.K. is supported by a Ruth L. Kirchenstein National Research Service Award postdoctoral fellowship provided by NIH (F32GM07782903). We thank E. Shaw for obtaining XPS spectra G. Henoch for providing the videos in the supporting online material and Y. Surendranath for many productive discussions.

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American Association for the Advancement of Science (AAAS)

Tập 321 Số 5892

1072-1075

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