In situ vanadium K-edge and tungsten LIII-edge X-ray absorption fine structure of vanadium-substituted heteropolytungstates immobilized in a high-area carbon electrode in acid aqueous electrolytes

D. E. Clinton, D. A. Tryk, I. T. Bae, F. L. Urbach*, M. R. Antonio, Daniel Alberto Scherson

*この研究の対応する著者

研究成果: Article査読

17 被引用数 (Scopus)

抄録

Electronic and structural aspects of vanadium-substituted heteropolytungstates immobilized in a high-area carbon (XC-72) as a function of oxidation state have been examined by in situ X-ray absorption near-edge structure (XANES) in an acidic electrolyte. The results obtained for K4PVW11O40 revealed a sizable shift in the V K-edge XANES region, which is characterized by a prominent pre-edge peak, following a one-electron reduction. Such behavior has been attributed to the transfer of an electron to an orbital localized mainly on vanadium. Injection of a second electron gives rise to the near disappearance of the pre-edge peak without major shifts in the position of edge jump, a phenomenon ascribed to an increase in the symmetry of the vanadium site upon reduction to yield a nearly octahedral environment. Similar behavior is observed for Cs6PV3W9O40 when the electrode is polarized in the potential regions where the vanadium ions are reduced to VIV and VIII, respectively. No changes in the in situ W LIII-edge XANES could be discerned for these vanadium-substituted heteropolytungstates in their various oxidation states, for which the spectral features were the same as those of H3PW12O40 adsorbed on XC-72 under otherwise identical conditions.

本文言語English
ページ(範囲)18511-18514
ページ数4
ジャーナルJournal of physical chemistry
100
47
出版ステータスPublished - 1996 11 21
外部発表はい

ASJC Scopus subject areas

  • 工学(全般)
  • 物理化学および理論化学

フィンガープリント

「In situ vanadium K-edge and tungsten L<sub>III</sub>-edge X-ray absorption fine structure of vanadium-substituted heteropolytungstates immobilized in a high-area carbon electrode in acid aqueous electrolytes」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

引用スタイル