Dopant Effects on Ceria Solar Thermochemical Water Splitting Behavior

Solar thermochemical water and carbon dioxide splitting provide a pathway to high efficiency solar fuels. To-date, ceria remains the benchmark material due to its stability and rapid kinetics. However, the low redox capacity of ceria has driven intense research into improving behavior. Here, we delve into the effects of dopant addition on the fundamental thermodynamic and kinetics of the water splitting process. We use quantum mechanical simulations to determine not only the effects of dopant addition, but the underlying cause. Though these models, we can see why some dopants are good, e.g. Zr, and why others are poor performers, e.g. Gd. This then can point towards novel materials design, particularly paired charge compensating dopants (PCCD). Additionally, experiment is used to test these new materials and validate computational results.