Combined Catalysis and Optical Screening for High Throughput Discovery of Solar Fuels Catalysts

Considerable research and development efforts are being devoted to the efficient generation of solar fuels. A solar fuels device couples a solar photoabsorber with catalysts to convert solar energy to chemical energy via reactions such as oxygen evolution (water splitting). Widespread deployment of this technology hinges upon discovery of new materials through efforts such as the high throughput screening of oxygen evolution catalysts, as discussed in this manuscript. We derive an expression for the efficiency of the oxygen evolution catalyst that combines catalytic and optical properties. Using this hybrid efficiency, we screen 5456 samples in a (Fe-Co-Ni-Ti)O_x pseudo-quaternary catalyst library using automated, high throughput electrochemistry and optical experiments. The observed compositional trends in this catalyst efficiency lead to the discovery of a new high performance composition region