The photoreduction of CO2 is an unconventional process to regenerate fuels and chemicals
storing solar radiation. A new photoreactor has been designed recently to achieve high
productivity during the process, i.e. up to 39 mol/h kgcat of HCOOH or 1.4 mol/h kgcat of CH3OH,
which are unprecedented results with respect to literature, especially with a very simple
commercial TiO2 catalyst.
The production of hydrogen through photoreforming of aqueous solutions of organic
compounds is also considered as a way to exploit solar energy storage in the form of hydrogen.
Different sugars were selected as substrates derived from the hydrolysis of biomass or from
wastewater (food or paper industry). A significant amount of H2 was obtained with very simple
catalyst formulations, e.g. 14 mol kgcat-1 h-1 were obtained at 4 bar, 80 \u2daC over commercial TiO2
samples, added with 0.1 mol% of Pt and using glucose as substrate. This result is very
remarkable with respect to similar research in conventional photoreactors.
Both the routes represent a circular way to regenerate valuable products from gaseous or liquid
wastes. Our attention was predominantly focused on the development of innovative reactors,
possibly operating under unconventional conditions, with fine tuning of the operation
parameters. The exploitation potential of these results under solar irradiation is presented
