Photocatalytic Dehydrogenation of Isopropanol on Pt/TiO2 Catalysts in Connection with Water Photosplitting

Isopropanol in the gas phase is photodehydrogenated at R.T. into acetone on metal (Pt)/TiO 2 catalysts. In the absence or in the presence of water vapour the amount of hydrogen produced is always equal to the amount of acetone. The presence of water vapour only increases the rate (to a limited extent) of the photodehydrogenation of isopropanol. In the liquid phase the rate of the photo-decomposition with Pt/TiO 2 catalysts is also increased in the presence of water, but water alone can be photodecomposed. Isopropanol is not a "sacrificial" compound for the reaction in the gas phase. For the liquid phase its role is not yet determined. The reaction in the gas phase and in the liquid phase exhibits some different behaviour.