Highly-dispersed ultrafine Pt nanoparticles on microemulsion-mediated TiO2 for production of hydrogen and valuable chemicals via oxidative photo-dehydrogenation of glycerol

The oxidative photo-dehydrogenation of glycerol to produce H2 and other valuable chemicals was studied using different materials. In particular, Pt nanoparticles were deposited on microemulsion-synthesized TiO2 via surface organometallic chemistry (SOMC) and compared with photocatalysts obtained using more conventional methods. Well-defined Pt(II) single-site titania-grafted were prepared reacting the surface hydroxyl groups of TiO2 nano-oxides with the organometallic Pt(COD)Me2 complex. Sample reduction under H2 generated ultrafine Pt nanoparticles well-dispersed on titania surface. Its performance under simulated solar light showed superior activity when compared to analogous Pt-containing catalysts prepared by other methods. Improved dispersion of Pt metal on titania surface was among the primary reasons of a better overall activity, providing relatively high rates of hydrogen productivity. Moreover, an increase of glyceraldehyde productivity in liquid phase was observed with the increase of Pt dispersion, demonstrating that the metal dispersion can strongly affect the selectivity of chemicals produced in the reaction. Comparison with state of the art shows that the present material exhibits excellent performance for a combined positive effect of the high specific surface area of titania prepared by microemulsion, giving access to the increased densities of active sites and the high dispersion of Pt nanoparticles given by the SOMC technique.