water electrolysis

evolution reaction

oxygen evolution reaction

membrane water

reaction oer

exchange membrane

density ma

oxide fuel

Nano Energy

The use of proton exchange membrane water electrolyzers (PEMWEs) is severely limited by large overpotentials and the low stability of their anode catalysts. The majority of the state-of-the-art anode catalysts have been tested in half-cells; however, it is highly desirable to design an anode catalyst that can be effectively employed in a real electrolyzer. Herein, a new structural design strategy is proposed as an effective pathway for constructing efficient and stable PEMWE anodes. The developed self-standing electrode with hierarchical structure comprises porous and defective RuO 2 nanosheets aligned on carbon fiber (RuO 2 -NS/CF) with several structural advantages, including large electrochemically active surface area, abundant defects, and exposed atoms/edges, and enhanced mass transfer capacity. Therefore, RuO 2 -NS/CF exhibits outstanding performance and durability for oxygen evolution reaction in acidic condition, and its mass activity is 60 times greater than that of commercial RuO 2 at an overpotential of 300 mV. Furthermore, the RuO 2 -NS/CF anode produces 2.827 A cm −2 at a voltage of 1.7 V cell during a single cell test, which considerably exceeds other reported catalysts. This work illustrates the significance of catalyst layer structure in electrocatalysis and sheds new light on the structural engineering of advanced catalysts. A structural design strategy is proposed as an effective method for constructing efficient and stable anode electrodes in PEMWE. The synthesized self-standing electrode with a hierarchical structure (RuO 2 -NS/CF) exhibits excellent catalytic activity and stability for oxygen evolution reaction in acidic condition and demonstrates an outstanding performance of 2.827 A cm −2 in 1.7 V cell as a PEMWE anode in single cell test. • Unravel the importance of catalysts layer structure in PEMWE. • Present an efficient strategy to construct hierarchical and defective RuO 2 . • The RuO 2 -NS/CF demonstrated an outstanding performance and stability for acidic OER. • The RuO 2 -NS/CF exh...

Structure engineering defective and mass transfer-enhanced RuO2 nanosheets for proton exchange membrane water electrolyzer