Screening of Lanthanum-Based Perovskites for the Oxygen Evolution Reaction at Industrial Conditions for Alkaline Water Electrolysis

Perovskites are broadly considered a promising class of catalysts for the oxygen evolution reaction (OER) in alkaline media. In particular, lanthanum-based perovskites, like La0.75Sr0.25MnO3-δ (LSMO), LaFeO3-δ (LFO), La0.6Sr0.4Fe0.98O3-δ (LSFO), La0.6Sr0.4Fe0.8Co0.2O3-δ (LSCFO) and La0.6Sr0.4Co0.99O3-δ (LSCO), have been researched as catalysts for the OER showing high catalytic activity. Stability assessment, on the other hand, is rarely carried out at industrial operating conditions, despite it being a precondition for industrial uptake. In this study, the material stability and intrinsic activity were evaluated at industrial alkaline water electrolysis conditions. LSMO showed high activity but instability due to Mn leaching. LSCFO and LFO demonstrated high activity at 75°C, but computational Pourbaix diagrams of both LFO and LSCFO predict instability at the operational potential window, which was confirmed during long-term stability testing. The overall findings highlight the importance of long-term testing at industrial operating conditions, as stability investigations at mild laboratory conditions are insufficient to qualify a candidate catalyst for industrial uptake.