Doped LaMnO3 for Water Splitting by Density Functional Theory Calculations

Current solar thermochemical reactors utilize CeO2-x in a two-step redox process. However, the high reaction temperature required for the use of CeO2 and the large temperature difference between the reduction and oxidation steps drives the search for other materials. Perovskite materials are promising candidates for such water splitting applications. The perovskite ABO3 formula yields multiple combinations of potential interest, with various A elements (lanthanides) and B elements (transition metals). In this work, focusing on LaMnO3, we make substitutions of Li, Na, K, Rb, Mg, Ca, Sr, Ba for La-sites and Mg, Zn, Al, Ga, In for Mn-sites. Density functional theory calculations are used to identify candidate materials for water splitting from all these compositions. Thermodynamic stability and oxygen vacancy formation energy (2.5 eV-5.0 eV) are used as criteria to select potential candidates.<br/> <br/>This work was supported by the Department of Energy, EERE DE-EE0008840.<br/><br/><b>Keywords: perovskite, doping, water splitting, density functional theory</b>