Super-ambient temperature gas phase photocatalysis

M/TiO2 photocatalysts (where M is Pt, Pd, Au and Ag) was used in a continuous flow gas phase photocatalytic system. Two main reactions were examined in detail, the reaction of water and methanol to form carbon dioxide and hydrogen, and the water gas shift reaction, i.e. the reaction of water and carbon monoxide to form carbon dioxide and hydrogen.

The catalysts were made via a wet impregnation method, typically between 0.01 to 10 wt.%. </p> <p> </p> <p>It was observed for both these reactions that as the metal loading increased so did the rate of reaction for hydrogen production. This usually occurred until the metal loading reached a loading of around 0.2-0.5 wt.%, where after this loading, say > 0.5 wt.% until around 1 or even 10 wt.%, the rate of reaction greatly plummets, until very little or no rate of hydrogen production is observed.