Photocatalytic Water Splitting Using Concentrated Sunlight: A Novel Test Facility

Kurzfassung

Background Photocatalytic water splitting employing solar radiation as the source of photons allows a carbon-neutral production of hydrogen. The project HyCats funded by the Federal Ministry of Education and Research of Germany aims at the design of highly efficient and stable photocatalysts as well as their application and investigation under practical conditions. Beside suspensions also photo-electrochemical cells with fixed-bed catalysts are considered. DLR develops a high-performance test facility including a 2-axis solar concentrator providing up to 20 suns on the surface of receiver/reactor-systems for reliable assessment of photocatalysts and photo-electrochemical cells. Design Different concentrator designs were analyzed employing a ray tracing tool with respect to the specifications. The key parameter to evaluate the potential of different concentrator/receiver-systems was the distribution of the radiation density on the surface of the receiver. A homogeneous distribution simplifies an accurate estimation of process efficiency and quantum yield. Results A concentrator/receiver-design featuring flat highly UV/Vis-reflective mirror strips and receivers with a flat irradiated surface was chosen. The current design of the test facility including performance details and peripheral equipment will be shown. Conclusion A novel test facility for the investigation of photocatalytic water splitting was designed and will be ready for operation in summer 2012.