P-31 SOLID-STATE NMR AND ESR INVESTIGATION OF TRIMETHYLPHOSPHANE ADSORPTION ON ZIRCONIA AND SULFATED ZIRCONIA

P-31 MAS NMR spectra of trimethylphosphane (TMP) adsorbed on monoclini c zirconia (ZrO2) and on tetragonal sulfated zirconia (ZrO2-S) were me asured. The P-31 NMR spectra show that protonic acidity, which does no t exist on ZrO2, is induced on ZrO2-S. Lewis acid centers on ZrO2-S ar e stronger than those on ZrO2. The formation of trimethylphosphane oxi de was also detected, indicating oxidizing properties of ZrO2-S that s ulfate-free ZrO2 does not possess. ESR spectra suggest the formation o f SO3- radical anions during TMP oxidation.