N2O decomposition over (CaO)(1-x)(MO)(x) oxide systems (M=Ti, Cr): Relation with photoluminescence
(EN)
Loukatzikou, L. A.
(EN)
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας
(EL)
Loukatzikou, L. A.
(EN)
(CaO)(1-x)(MO)(x) oxide systems (M = Ti, Cr, x = 0-1), prepared at 1150 degrees C under atmospheric conditions, were investigated for their photoluminescence as well as for their catalytic activity in N2O decomposition in the temperature range 400-650 degrees C. As shown by XRD analysis, the solids are either multicomponent systems or simple phase oxides. Titanium addition to CaO of up to 30% results in a significant enhancement of the catalytic activity, while chromium addition beyond 1% has the reverse effect; solids rich in Ti or Cr are rather inactive. Thus, the systems showing considerable activity are either simple phase CaO, or CaO-CaTiO3 mixed oxides. The photoluminescence intensity of the catalysts was found to be suppressed by addition of Cr or Ti (>0.5%) to CaO. Although the catalytic activity is affected in different ways by addition of Ti or Cr, and a variety of structural composition are noted for the (CaO)(1-x)(MO)(x) catalysts, a relation between catalytic activity and photoluminescence is observed, not only across each sample series, but also for the total set of catalysts.
(EN)