Quantum efficiency of cyanide photooxidation with TiO2/SiO2 catalysts: Multivariate analysis by experimental design

MARUGAN, J.; VAN GRIEKEN, R.; ALFANO, O.M.; CASSANO, A.E.

Las Palmas de Gran Canaria, España

Congreso; 4th European Meeting on Solar Chemistry and Photocatalysis: Environmental Applications - SPEA4; 2006

The absolute quantum efficiency (h) of a photocatalytic reaction is defined as the ratio between the experimental volumetric molar reaction rate of the process (r) and the volumetric rate of photon absorption by the semiconductor catalyst (ea). This parameter describes the most intrinsic activity of the material and the efficiency in the use of photons. However, despite the large number of supported TiO2 photocatalysts reported in the last years, not many attempts have been made for the estimation of h for this kind of materials. This work deals with the determination of the absolute quantum efficiency for free cyanide photooxidation with silica-supported TiO2 photocatalysts. The influence of initial concentration of cyanide, catalysts concentration and incident photon flux has been study by using a statistical approach with a two level factorial design and central point. The main advantage of these statistical techniques is that the obtained mathematical model allows the optimization of the operational conditions minimizing the number of experiments.