Photoassisted Water-Gas Shift Reaction on Platinized Titania: The Influence of Preparation Parameters

摘要

The variation of the rate of the photoassisted water-gas shift reaction over platinized titania with changes in catalyst preparation has been studied - The following parameters were varied: (1) extent of hydrogen reduction; (2) Pt loading; (3) method of depositing Pt; (4) light intensity; and (5) NaOH loading. The reaction rate does not depend on the method of Pt deposition; is first order in light intensity; is not dependent on the chemical state or the Pt loading above 2 wt.%; depends on reduction of the titania and is strongly dependent on the surface concentration of NaOH. From this work, we conclude that when NaOH is present, the rate limiting step in the reaction is the reaction of photoproduced holes with surface OH(-) ions. (Author)