898267-05-5Relevant articles and documents
Water oxidation with molecularly defined iridium complexes: Insights into homogeneous versus heterogeneous catalysis
Junge, Henrik,Marquet, Nicolas,Kammer, Anja,Denurra, Stefania,Bauer, Matthias,Wohlrab, Sebastian,Gaertner, Felix,Pohl, Marga-Martina,Spannenberg, Anke,Gladiali, Serafino,Beller, Matthias
, p. 12749 - 12758 (2012)
Molecularly defined Ir complexes and different samples of supported IrO2 nanoparticles have been tested and compared in the catalytic water oxidation with cerium ammonium nitrate (CAN) as the oxidant. By comparing the activity of nano-scaled supported IrO2 particles to the one of organometallic complexes it is shown that the overall activity of the homogeneous Ir precursors is defined by both the formation of the homogeneous active species and its conversion to IrIV-oxo nanoparticles. In the first phase of the reaction the activity is dominated by the homogeneous active species. With increasing reaction time, the influence of nano-sized Ir-oxo particles becomes more evident. Notably, the different conversion rates of the homogeneous precursor into the active species as well as the conversion into Ir-oxo nanoparticles and the different particle sizes have a significant influence on the overall activity. In addition to the homogeneous systems, IrO2@MCM-41 has also been synthesized, which contains stabilized nanoparticles of between 1 and 3 nm in size. This latter system shows a similar activity to IrCl3·xH2O and complexes 4 and 5. Mechanistic insights were obtained by in situ X-ray absorption spectroscopy and scanning transmission electron microscopy. Ir walks a fine line: Molecularly defined Ir complexes and IrO2 nanoparticles have been applied in the water oxidation reaction with cerium ammonium nitrate (CAN) as oxidant and compared (see scheme). The conversion of the first to the latter has been investigated by means of XANES, EXAFS, and STEM. Copyright
PHOTOSENSITIZERS AND USE THEREOF FOR GENERATING HYDROGEN FROM WATER
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Paragraph 0049; 0050, (2014/02/16)
The invention relates to novel complexes and to the use thereof as photosensitizers for generating hydrogen from water.