LIQUID-PHASE OXIDATION OF ALCOHOLS BY DIOXYGEN USING OXIDE-SUPPORTED PLATINUM CATALYSTS

Alkaline earth oxide (MgO, CaO, BaO)-supported platinum catalysts disp layed higher activity in the oxidation of alcohols such as 1-butanol, 1-hexanol, cyclopentanol and cyclohexanol under mild conditions than n eutral oxide (SiO2, Al2O3) supported platinum catalysts. MgO-Pt cataly st could be recycled in the oxidation without noticeable decrease of i ts activity. Further investigation of MgO-Pt and SiO2-Pt by TEM and XP S showed that lower valent (mainly Pt(0)), smaller, and more homogeneo usly dispersed platinum particles tended to form on MgO than on SiO2. This indicated that the oxide in the oxide-Pt catalysts played an impo rtant role in controlling the dispersion and valence of platinum, cons equently strongly influencing the activity of oxide-Pt catalysts.