Advanced search
Start date

Ironporphyrins-titanium supported on clay or silica matrices for photocatalytic production of hydrogen peroxide


The demand for hydrogen peroxide is increasing worldwide. Although it is considered a "green" chemical, its synthesis is environmentally unfriendly. Direct hydrogen peroxide synthesis is the most effective way to overcome this issue, but factors such as water formation, risk of explosion, and poor hydrogen peroxide stability prevent this process from being applied at the industrial level. This research project will be conducted in collaboration with researchers from the University of Salamanca and the Public University of Navarra - Spain (please see the attached collaboration letter). We will prepare efficient and selective photocatalysts that can produce hydrogen peroxide directly, thus avoiding its deactivation and optimizing the properties and advantages of TiO2. First, we will functionalize TiO2 with organosilanes and covalently bind an a second-generation ironporphyrin to the resulting material. Next, the hybrid ironporphyrin- or porphyrin-TiO2 nanoparticles will be dispersed in porous solid supports such as kaolinite, sepiolite, or earth diatom, to increase exposure of the photoactive species (TiO2 and ironporphyrin) in the photocatalyst to the reactants. The high porosity of the photocatalyst support will ensure that hydrogen peroxide will be formed without being deactivated. The photocatalysts will be characterized by chemical analysis, X-ray diffraction, physiosorption methods, scanning electron microscopy, thermal analysis, absorption spectroscopy in the infrared and UV-Vis regions. The outcomes of direct hydrogen peroxide synthesis in the presence of the photocatalysts will be related to each photocatalyst's properties, which will be established by the characterization techniques. The outcomes will also be rationalized in terms of the mechanism of action of the ironporphyrin as passivator of the TiO2 surface and of their ability to create new sites for O2 reduction. Additionally, the influence of the support on the surface properties of TiO2 will be assessed. Finally, whether inhibition of the electron-vacancy pair improves the photocatalytic efficiency will be evaluated. We believe that the photocatalysts we will prepare in this project will prove promising alternatives to synthesize hydrogen peroxide in the presence of TiO2 covalently bound to easy-to-synthesize ironporphyrins supported on widely available and non-toxic supports. We also hope to elucidate the role that even low concentrations of ironporphrin play in the passivation of the TiO2 surface. (AU)

Articles published in Agência FAPESP Newsletter about the research grant:
Articles published in other media outlets (0 total):
More itemsLess items