Discovery of Oxygen Carriers by Mining a First-Principle Database

Chemical looping is an innovative technique that relies,to a largeextent, on the possibility of finding new oxygen carriers. Until now,these materials have primarily been identified via experimental techniquesand therefrom derived insights. However, this is both costly and time-consuming.To speed-up this process, we have applied a computational screeningapproach based on energetic data retrieved from the Open Quantum MaterialsDatabase. In particular, we have considered combinations of all mono-,bi-, and trimetallic alloys and mixed oxides with up to three distinctivephases. Here, we specifically focus on a technique referred to aschemical looping oxygen uncoupling, which is especially suitable forsolid fuels, e.g., combustion of biomass for negative CO2 emissions. The formation energies obtained for the materials ofinterest were used to identify phase transitions that are likely tooccur under conditions relevant for chemical looping oxygen uncoupling.Given these criteria, the initial list of 300000 materials is reducedby a factor of 20, and after filtering out rare, radioactive, toxic,or harmful elements only 1000 remain. When considering the abundanceof elements in the ranking criteria, most of the highest ranking phasesinclude Cu, Mn, and Fe. This adds credibility to the procedure, asmany viable oxygen carriers for chemical looping oxygen uncouplingthat have been studied experimentally contain these elements. WhileCr-based materials have not been widely explored for this application,our study suggests that this might be worthwhile since these occurmore frequently than Fe. Other elements that would be interestingas additional components include Ba, K, Na, Al, and Si.