Enhanced photocatalytic hydrogen production in a UV-irradiated fluidized bed reactor

- UV-irradiated fluidized bed reactor with Pt-loaded TiO2 sphere catalyst is developed.
- Fluidized bed reactor system is explored for photocatalytic hydrogen generation.
- This reactor minimizes the parasitic back reaction and radiation distribution effects.
- Pt-loaded TiO2 spheres greatly improve the apparent quantum efficiency (AQE).
- Improvement in AQE results from the enhanced separation of the evolved H2 and O2.

UV-irradiated fluidized bed reactor system and Pt-loaded TiO2 spheres were developed for photocatalytic water splitting. This novel approach was explored as a means to minimize the parasitic back reaction, mass transport and radiation distribution effects that limit the performance and scalability of immobilized-film and suspended slurry photocatalysts typically employed for photocatalytic hydrogen production. By fluidizing Pt-loaded TiO2 spheres in a 2.2 M Na2CO3 solution, steady hydrogen production rates up to 211 μmol/h with an apparent quantum efficiency of 1.33% were achieved upon UV-irradiation. This demonstrates a marked 44% increase in the apparent quantum efficiency when compared to the performance of a traditional Pt-loaded TiO2 suspended slurry photocatalyst in the same reactor. It is hypothesized that this enhanced performance is primarily due to improved separation of the evolved H2 and O2 from the Pt-loaded photocatalyst particles, thus reducing the parasitic back reaction.

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