H2 production by renewables photoreforming on Pt-Au/TiO2 catalysts activated by reduction

Bimetallic PtAu nanoparticles supported on reduced anatase nanocrystals represent a new class of promising photocatalysts with high activity in hydrogen production by photoreforming of aqueous solution of renewable feedstock, such as ethanol and glycerol. The catalysts are easily obtained by metal impregnation of commercial TiO2, followed by a reductive treatment. Remarkably, deeper catalyst pre-reduction results in enhanced photoactivity. When ethanol is used as sacrificial agent, under both UV-A or simulated sunlight irradiation, H2 is the most abundant product in the gas stream whereas, in the case of glycerol, significant amounts of CO2 have also been detected, indicating a more efficient oxidation of the organic sacrificial agent. The presence of bimetallic PtAu nanoparticles and of Ti3+ sites/O2- vacancies in the bulk structure of titania are two key parameters to maximize light absorption and feedstock activation, finally resulting in good photocatalytic performances.