A highly active and stable La_0.5Sr_0.5Ni_0.4Fe_0.6O_3-δ perovskite electrocatalyst for oxygen evolution reaction in alkaline media

Owing to the slow kinetics of oxygen evolution reaction (OER), developing highly active and stable OER catalysts is of great importance to realize the industrial operation for water electrolysis, reversible fuel cells and so on. Here, we report a highly active and stable La_0.5Sr_0.5Ni_0.4Fe_0.6O_3-δ perovskite electrocatalyst for OER in alkaline media. La_0.5Sr_0.5Ni_xFe_1-xO_3-δ (LSNF) perovskites with different Ni/Fe ratio were synthesized by a typical sol-gel route and investigated as potential cobalt-free OER perovskite electrocatalysts. Synchrotron XRD quantification analysis was applied to quantify the crystal structural details and changes. La_0.5Sr_0.5Ni_0.4Fe_0.6O_3-δ (LSNF-5546) materials show significantly higher intrinsic activities and better stability in 0.1 M KOH for the OER including onset potential (1.56 V) and Tafel slope (76 mV/dec), higher than that of other LSNF and state-of-the-art perovskite electrocatalyst Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3-δ (BSCF-5582). This work demonstrates that La_0.5Sr_0.5Ni_0.4Fe_0.6O_3-δ (LSNF-5546) can be a new kind of cost-effective and high-performance perovskite electrocatalyst for OER in alkaline solution, and the simple doping strategy would be a practical way to enhance oxygen evolution on perovskite electrocatalysts.