Enhancing Bifunctional Electrocatalytic Activities of La_0.5Sr_0.5Co_0.2Fe_0.8O₃ in Reversible Single-Component Cells

Abstract

Perovskite La0.5Sr0.5Co0.2Fe0.8O3 (LSCF) usually acts as both cathode and anode in a reversible solid oxide cell (RSOC). It is found that the traditional preparation method can be improved to reduce the particle size, increase the specific surface area, and enhance the oxygen vacancy concentration of LSCF, further improving its bifunctional electrocatalytic activity toward oxygen reduction reaction (ORR) and hydrogen oxidation reaction (HOR). Compared with that of LSCF prepared by the traditional solid-state reaction method, the oxygen vacancy concentration of LSCF prepared by the hard-template method is increased. Moreover, the LSCF prepared by the hard-template method shows better catalytic activity for HOR and ORR. In addition, the rate-determining steps for HOR and ORR on the surface of LSCF prepared by the hard-template method are the charge transfer reaction and the reduction of oxygen atoms to O–, respectively. Furthermore, a single-component fuel cell and a reversible single-component cell composed of LSCF prepared by the hard-template method exhibit better performance for discharge and water electrolysis.