Microemulsions in the preparation of highly active combustion catalysts

Catalytic activity in combustion of toluene in toluene–air mixtures and physical–chemical properties of platinum catalysts prepared from reverse microemulsions (water-in-oil) and by classical impregnation from water solutions of H₂PtCl₆ were studied. Microemulsion catalysts were more active than those prepared classically from water solutions. Size of Pt in classically impregnated catalysts was three times higher than that of catalysts prepared from microemulsions. In case of microemulsion preparation method, platinum is located near the pellet surface or its position in the pellet can be optimised. The effect of oil used in microemulsion system seems to be negligible for the activity of the catalysts with 0.1 wt.% Pt.