Molecular versus Silica‐Supported Iridium Water Oxidation Catalysts
نویسندگان
چکیده
A stringent comparison between two pairs of molecular/immobilized water oxidation catalysts reveals distinctive catalytic trends. While the molecular compound 1 exhibits a substantial higher activity than analogous immobilized system 1_SiO2, under all experimental conditions explored, contrary is found with 2 that far less active its counterpart 2_SiO2. This explained by unique tendency to form dimeric complexes [Cp*Ir-(κ2-µ2-Hpysa)(κ2-µ2-pysa)IrCp*], 2a, in phosphate buffered solution at pH 7, and [Cp*Ir-(κ2-µ2-Hpysa)2IrCp*], 2b,in water. 2a 2b have been completely characterized multinuclear multidimensional NMR spectroscopy. They also isolated as single crystals their structure solid state determined X-Ray diffractometry. appear be off-cycle species, whose formation detrimental for activity, indicated observation long induction period when used precursor. In addition, TOF versusΔE trends first runs do not overlap catalyst TOFmax remarkably second run upon addition fresh NaIO4. 2_SiO2 associative processes are likely inhibited leading an 2.
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ژورنال
عنوان ژورنال: European Journal of Inorganic Chemistry
سال: 2023
ISSN: ['1434-1948', '1099-0682']
DOI: https://doi.org/10.1002/ejic.202300211