Interfacial Ru centers coupling with oxygen vacancies in VO-RuO2@CA hybrid aerogel boosts acidic water oxidation

The exploitation of highly active, cheap cost and durable electrocatalyst for acidic water oxidation reaction still presents a major technological and scientific challenge in proton exchange membrane water electrolysers (PEMWEs). Herein, a hybrid aerogel of oxygen defect-rich RuO 2 nanoparticles coupling with carbon (V O -RuO 2 @CA) was designed to promote their activity and stability during acid water oxidation. The optimized V O -RuO 2 @CA achieves an ultralow overpotential of 207 mV at 10 mA cm −2 for acidic water oxidation and sustains a prominent long-term stability during the 30 h chronopotentiometry test in 0.5 M H 2 SO 4 . Furthermore, V O -RuO 2 @CA exhibits high mass activities of 186.5 mA mg Ru −1 and TOF values of up to 2.07 s − 1 at an overpotential of 300 mV, being 17.7 and 4.8 times higher than commercial RuO 2 , respectively. Theory calculations and experimental results verify that the oxygen vacancies (V O ) could significantly weaken the binding energy of O* with respect to OOH* for the interfacial Ru centers between RuO 2 and carbon, rendering the increase of the intrinsic water oxidation activity and resistance to over-oxidation for RuO 2 . This research provides a novel pathway to explore remarkably efficient 3D porous hybrid aerogel electrocatalysts toward anodic electrocatalysts applications in PEMWEs.