Lanthanides Regulate the Oxide Pathway Mechanism of RuO ₂ to Boost Acidic Oxygen Evolution

Regulating the reaction pathway of the oxygen evolution reaction (OER) is pivotal in enhancing the activity and stability of RuO 2 -based catalysts. However, it remains challenging to achieve the desired oxide pathway mechanism (OPM) for RuO 2 -based catalysts. Herein, we use density functional theory calculations to predict that Sm doping can tune the OER pathway of RuO 2 toward the OPM. We successfully synthesize various lanthanide-doped RuO 2 catalysts and demonstrate an overpotential as low as 184 mV at 10 mA cm –2 for Sm-doped RuO 2 supported on reduced graphene oxide (Sm-RuO 2 /rGO). Sm-RuO 2 /rGO exhibits a stable operation for over 200 h at 500 mA cm –2 . In situ characterizations confirm the functionality of incorporated Sm atoms in triggering an OPM pathway for RuO 2 . Our work demonstrates an effective strategy to regulate the OER pathway of RuO 2 -based catalysts, enabling highly efficient and durable OER under acidic conditions and showing great promise for industrial applications.