Institute of Solid State Physics

Latvian Council of Science

Coordinator: Denis Gryaznov

Duration: 2022-2024

The climate change is unprecedentedly important issue for our planet. One of the approaches is based on the development of effective green technologies. Solid oxide electrolysis cells (SOECs) are used to convert CO₂ into useful, chemically valuable materials and other products by the electrochemical process.  Besides, the SOECs can be used in either oxide ion conduction or proton conduction (PCEC) mode. The latter mode is of particular interest as it offers possibilities for the co-electrolysis and intermediate temperature regimes due to higher proton conductivities of electrolyte materials. Presently, the greatest challenge for the SOECs technologies is the performance degradation at high temperatures and cost. The main goal of the proposed theoretical project is prediction of new PCEC anode materials on the basis of mixed ion-electron hole conducting oxides for inter-mediate temperatures (300-600 C). Therefore, we consider Ruddlesden-Popper phases (Sr,La)_n+1Fe_nO_3n+1 with variation of phase order n as effective anodes materials for the PCECs. The following issues will be uncovered: (i) relations between crystal structure and properties for high proton and p-type electronic conductivity; (ii) proton incorporation mechanisms by acid-base or by redox reaction; (iii) chemical and thermal expansion issues accompanying water incorporation; (iv) development and applications of evolutionary algorithms for accurate defect structures in density functional theory calculations.