Photocatalytic dehydrogenation of liquid propan-2-ol by platinized anatase and other catalysts

Abstract

The photocatalytic dehydrogenation of liquid propan-2-ol by suspensions of platinum and other metals supported on anatase has been investigated by following propanone formation under an N₂ atmosphere. Measurements were made over the range 278–303 K using filtered 366 nm u.v. radiation.

With Pt/TiO₂ prepared by H₂ reduction there was an appreciable dark reaction, which was absent with catalysts prepared by photodeposition. Reaction on photodeposited catalysts was consistently associated with an activation energy of 20 kJ mol^–1, although the activity fell in the sequence Pt/TiO₂ > Pd/TiO₂ > Rh/TiO₂ > Au/TiO₂= 0 for catalysts with a metal content of 0.5 wt%. The activation energy is identical to that for photoreaction on the anatase support in the presence of O₂ and is believed to be associated with the transport of photoelectrons through the anatase to either metal particles or adsorbed O₂.