Discovery of Oxygen Carriers by Mining a First-Principle Database

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