Breaking the Activity-Stability Trade-off in Acidic OER via Mechanism Switching on Mo-Doped RuO 2

High Resolution Image Download MS PowerPoint Slide Ruthenium oxide (RuO 2 ) is currently regarded as the preferred catalyst for the oxygen evolution reaction (OER) under acidic conditions. However, it faces issues of overoxidation and dissolution during the reaction process. Therefore, developing highly efficient and durable bifunctional electrocatalysts is crucial for acidic water electrolysis hydrogen production. This work reports a Ru–Mo bimetallic catalyst that enhances performance and stability in the acidic oxygen evolution reaction (OER) by incorporating Mo into RuO 2 . The optimized Ru 1 Mo 1 –O/C exhibits an overpotential of only 167 mV at a current density of 10 mA·cm –2, significantly lower than that of commercial RuO 2 (354 mV), with a Tafel slope of 57.7 mV·dec –1, indicating fast kinetic rates. Furthermore, Ru 1 Mo 1 –O/C maintains durability for 255 h in 0.5 M H 2 SO 4 solution, offering a breakthrough in addressing the durability issue of ruthenium-based catalysts. Through the H/D isotope effect, we demonstrate that Mo incorporation accelerates proton reaction kinetics, providing strong evidence for suppressing Ru overoxidation.