INFLUENCE OF CATALYST PARAMETERS AND OPERATIONAL VARIABLES ON THE PHOTOCATALYTIC CLEAVAGE OF WATER

The photocatalytic cleavage of water over Pt-RuO2/TiO2 catalysts under illumination in the near UV (250-400 nm) is investigated in a batch and in a semicontinuous flow photoreactor cell. The effects of operational variables and parameters related to chemical and physical characteristics of the catalyst on the rate of hydrogen production are investigated. It is shown that the rate of the process is insensitive to the details of surface structure of Pt; the rate exhibits a weak maximum at a Pt loading of 0.5 wt% and is independent of Pt loading when this exceeds 1 wt%. The rate of H2 production is strongly dependent on the pH of the slurry, increasing significantly at pH levels higher than 10. The rate was also observed to be a linear function of the intensity of illumination in the near UV. © 1992.