Investigating the activity of modified TiO2 photocatalysts used for the photoreforming of biomass derivatives

Different TiO2 modified (with Pt, Cu2O, Nb) photocatalysts have been compared for the photo-reforming of glucose and fructose at ambient conditions with the aim of linking the photoactivity to some structural and surface characteristics. A different degree of conversion, distribution of intermediates and H2 production were observed with the various photocatalysts. Moreover, the results obtained with the same catalysts were slightly different with the two substrates, highlighting the importance of the interaction between the catalyst surface and the organic compound. Bare TiO2 was inactive towards H2 production, Cu2O was effective in replacing Pt for hydrogen generation, and the presence of Pt/Nb was beneficial for both H2 production and selective oxidation. Moreover, Pt not only works as a sink for the photoproduced electrons, as it is well known in the literature, but also modifies the surface acid-base properties of catalysts as revealed by DRIFT and TPD measurements.