Stability and Exsolution of Sr0.98Ti0.7Fe0.25Ni0.05O3 for the Oxygen Evolution Reaction in an Alkaline Environment

Developing stable, critical raw material lean catalysts for the OER is essential for low-cost green hydrogen production. In this study, dense, polished pellets of Sr_0.98Ti_0.7Fe_0.25Ni_0.05O₃ (STFNO) were employed as a model system to investigate intrinsic OER activity and stability under industrially relevant conditions. The well-defined surface and controlled interface between the sample and electrolyte represent a more fundamental approach to studying catalytic performance. Testing was conducted at elevated temperatures up to 150 °C and at a pressure of 50 bar, offering unique insights into catalytic activity and stability under harsh conditions. STFNO demonstrated excellent stability during prolonged testing and high catalytic activity. This study also explored the role of exsolution in enhancing OER performance under industrially relevant conditions. Homogeneous (Ni,Fe)O_x nanoparticles, exsolved at 600 °C, yielded a notably low overpotential of 199 mV at 75 °C. These findings provide valuable insights into the activity and stability of STFNO as an industrially viable catalyst.