RuO2/CoMo2Ox Catalyst with Low Ruthenium Loading for Long-Term Acidic Oxygen Evolution

We must urgently synthesize highly efficient and stable oxygen-evolution reaction (OER) catalysts for acidic media. Herein, we constructed a series of Ti mesh (TM)-supported RuO2/CoMoyOx catalysts (RuO2/CoMoyOx/TM) with heterogeneous structures. By optimizing the ratio of Co to Mo, RuO2/CoMo2Ox/TM with low Ru loading (0.079 mg/cm(2)) achieves remarkable OER performance (eta = 243 mV at 10 mA/cm(2)) and high stability (300 h @ 10 mA/cm(2)) in 0.5 mol/L H2SO4 electrolyte. The activity of RuO2/CoMoyOx/TM can be maintained for 50 h at 100 mA/cm(2), and a water electrolyzer with RuO2/CoMo2Ox/TM as anode can operate for 40 h at 100 mA/cm(2), suggesting the remarkable OER durability of RuO2/CoMoyOx/TM in acidic electrolyte. Owing to the heterogeneous interface between CoMo2Ox and RuO2, the electronic structure of Ru atoms was optimized and electron-rich Ru was formed. With modulated electronic properties, the dissociation energy of H2O is weakened, and the OER barrier is lowered. This study provides the design of low-cost noble metal catalysts with long-term stability in an acidic environment.