Discovery of Novel Materials for Solar Thermochemical Fuels

Introduction The use of hydrogen as a clean and sustainable fuel depends on an efficient and inexpensive method of producing the gas. Currently, most hydrogen is produced from steam reformation with hydrocarbons, where water splitting (hydrolysis) is performed by reacting steam to carbon-based fuels. To avoid the use of hydrocarbons and greenhouse gas emissions, hydrolysis is also possible through electrolysis (the use of electricity to drive the splitting of the H2O molecule) or thermochemical water splitting (reacting steam with a reduced oxide). In both cases, the only byproduct is oxygen and they can both be powered from solar energy. Electrolysis, however, requires the conversion of solar energy to electricity before hydrolysis, which can degrade the efficiency of the system. Thermochemical water splitting, on the other hand, directly employs the solar energy, offering potentially higher efficiencies.