Solar hydrogen production from ethanol-water vapours over metal/TiO2 photocatalysts supported on ?-SiC alveolar foams

In this work, we have explored the feasibility of alveolar open-cell beta-SiC foams as catalyst support for solar hydrogen production. For that purpose, Pt and Ru nanoparticles have been obtained, by means of photoassisted synthesis, on TiO2-coated foams and tested in gas-phase hydrogen production from water-ethanol mixtures in a tubular reactor coupled to a compound parabolic solar collector (CPC). Subnanometre-sized metal or metal/ oxide nanoparticles are obtained for Pt/TiO2/SiC and Ru/TiO2/SiC foams, respectively, where co-catalyst nanoparticles decorate the TiO2 coating which in turn is attached to the SiC foam through an amorphous SiO2 washcoat formed by SiC pre-calcination. In solar photocatalytic reactions, all of the assayed foam-supported photocatalysts are active for the production of hydrogen, with Pt/TiO2 ones being the most active and foam pore size exerting little influence on hydrogen outcome. In the best conditions, 14 % UV-to-hydrogen (equivalent to 0.49 % solar-to-hydrogen) conversion efficiency, with photonic efficiency higher than 30 %, is attained.

Automated summary

In this study, the feasibility of using alveolar open-cell beta-SiC foams as a catalyst support for solar hydrogen production was explored. Pt and Ru nanoparticles were obtained through photoassisted synthesis and tested for gas-phase hydrogen production from water-ethanol mixtures. The foam-supported photocatalysts, including Pt/TiO2 and Ru/TiO2, showed activity in solar photocatalytic reactions, with Pt/TiO2 being the most active. The foam pore size had little influence on hydrogen outcome, and a UV-to-hydrogen conversion efficiency of 14% (equivalent to 0.49% solar-to-hydrogen) was achieved under the best conditions, with a photonic efficiency higher than 30%.