REDUCIBILITY OF MO SPECIES IN PT MOO3 AND PTMO/AL2O3 CATALYSTS/

Reducibility of Mo species in Pt/MoO3 and PtMo/Al2O3 has been investig ated by temperature-programmed reduction (TPR), temperature-programmed desorption of hydrogen (H-2-TPD) and temperature programmed electroni c conductivity (TPEC) techniques. In Pt/MoO3 at H-2 atmosphere, it was found by TPEC and TPR that, a slight amount of Pt could activate the transfer of the species and H atoms between H-2 and MoO3, and thus acc elerate the reduction of MoO3. In PtMo/Al2O3, TPR and H-2-TPD revealed that the reduction of surface Mo species could also be facilitated by Pt. Two kinds of hydrogen molybdenum species were proposed on the sur face of the catalyst after prereduction.