Solid state and solution 43Ca NMR of calcium peroxides involved in the disproportionation of hydrogen peroxide by calcium hydroxide.
In order to get some insight into the mechanism of the disproportionation of hydrogen peroxide catalyzed by calcium hydroxide, 43Ca NMR spectra of enriched samples of calcium peroxides and of their precursors have been studied in both solution and solid state. This study demonstrates that no well-defined peroxidized calcium species are formed in solution, showing that the catalytic role of calcium is likely restricted to the solid state. Most of the calcium compounds that could be involved in the catalytic process have been investigated with solid state NMR. The shift and quadrupolar parameters of Ca(OH)2, CaO2.8H2O and CaO2.2H2O2 are reported for the first time. These parameters are different enough to allow the quantitative analysis of a complex mixture of these compounds by NMR.
Trokiner
Arlette
A
Laboratoire de Physique du Solide, UPR CNRS A05, ESPCI, 10 Rue Vauquelin, F-75231 Paris 05, France. arlette.trokiner@espci.fr
Bessière
Aurélie
A
Thouvenot
René
R
Hau
Damien
D
Marko
Jean
J
Nardello
Véronique
V
Pierlot
Christel
C
Aubry
Jean-Marie
JM
D002126:Calcium Hydroxide / Q000032:analysis / Q000737:chemistry*; D002127:Calcium Isotopes; D002384:Catalysis; D006861:Hydrogen Peroxide / Q000032:analysis / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D010084:Oxidation-Reduction; D010545:Peroxides / Q000032:analysis / Q000737:chemistry*; D044367:Phase Transition; D012996:Solutions; D014867:Water / Q000737:chemistry*
D002127:Calcium Isotopes; D010545:Peroxides; D012996:Solutions; D014867:Water; C403632:calcium peroxide; D006861:Hydrogen Peroxide; D002126:Calcium Hydroxide