Design of Ruddlesden–Popper Oxides with Optimal Surface Oxygen Exchange Properties for Oxygen Reduction and Evolution

Abstract

Electrochemical high-temperature oxygen reduction and evolution play an important role in energy conversion and generation using solid oxide electrochemical cells. First-series Ruddlesden–Popper (R-P) oxides (A2BO4) have emerged as promising electrocatalysts for these reactions due to their suitable mixed ionic and electronic conductivities. However, a detailed understanding of the factors that govern their performance is still elusive, making their optimization challenging. In the present work, a systematic theoretical study is used to investigate the underlying factors that control the process of surface oxygen exchange, which governs oxygen reduction and evolution on these oxides. The effects of A- and B-site composition and surface termination of these oxides on their activities are elucidated. Among the different compositions, Co-based, B-site-terminated R-P oxides are predicted to exhibit the highest activity due to providing the best compromise between the energetics associated with oxygen dissocia...