Heterogenized water oxidation catalysts prepared by immobilizing Klaui-type organometallic precursors

View/Open
Document typeArticle
Defense date2016-09-12
Rights accessOpen Access
Abstract
An efficient heterogenized water oxidation catalyst (2_TiO2) has been synthesized by immobilizing the Kläui-type organometallic precursor [Cp*Ir{P(O)(OH)2}3]Na (2, Cp*=1,2,3,4,5-pentamethylcyclopentadienyl ligand) onto rutile TiO2. Iridium is homogeneously distributed at the molecular and atomic/small cluster level in 2_TiO2 and 2'_TiO2 (solid catalyst recovered after the first catalytic run), respectively, as indicated by STEM-HAADF (scanning transmission electron microscopy - high angle annular dark field) studies. 2'_TiO2 exhibits TOF values up to 23.7 min-1 in the oxidation of water to O2 driven by NaIO4 at nearly neutral pH, and a TON only limited by the amount of NaIO4 used, as indicated by multiple run experiments. Furthermore, while roughly 40¿% leaching is observed during the first catalytic run, 2'_TiO2 does not undergo any further leaching even when in contact with strongly basic solutions and completely maintains its activity for thousands of cycles. NMR studies, in combination with ICP-OES (inductively coupled plasma optical emission spectrometry), indicate that the activation of 2_TiO2 occurs through the initial oxidative dissociation of PO43-, ultimately leading to active centers in which a 1:1 P/Ir ratio is present (derived from the removal of two PO43- units) likely missing the Cp* ligand.
CitationPastori, G., Wahab, K., Bucci, A., Bellachioma, G., Zuccaccia, C., Llorca, J., Idriss, H., Macchioni, A. Heterogenized water oxidation catalysts prepared by immobilizing Klaui-type organometallic precursors. "Chemistry: a european journal", 12 Setembre 2016, vol. 22, núm. 38, p. 13459-13463.
ISSN0947-6539
Publisher versionhttp://onlinelibrary.wiley.com/doi/10.1002/chem.201602008/abstract
Files | Description | Size | Format | View |
---|---|---|---|---|
alceo+2016.pdf | 494,2Kb | View/Open |
Except where otherwise noted, content on this work
is licensed under a Creative Commons license
:
Attribution-NonCommercial-NoDerivs 3.0 Spain