Selective liquid phase oxidation using gold catalysts

Au/C and Au/oxide (Al2O3, TiO2) have been compared in the liquid phase oxidation of glycols and a different trend in reactivity revealed. On the oxides the activity of supported gold increases by decreasing particle size, whereas on carbon maximum activity is achieved with gold particle mean diameter around 7-8 nm. XPS revealed that in the latter case activity depends not only on the size of the gold particle but also on its surface concentration.