Epitaxial Growth of PdH@Ru Hollow Nanobamboos for Efficient Hydrogen Evolution in Anion Exchange Membrane Electrolyzer

In-depth comprehension and improvement of the sluggish hydrogen evolution kinetics in alkaline media is highly important to enhance the activity and durability of anion exchange membrane water electrolysis (AEMWE) for green hydrogen production. Herein, a hydrogen atom-terminated core-shell PdH@Ru nanobamboos (NBs) is developed by the synergetic strategy of epitaxial growth and in situ DMF hydrogenation. The synthesized PdH@Ru NBs demonstrate exceptional activity for hydrogen evolution reaction (HER) in alkaline media, requiring only a 14 mV overpotential at the 10 mA cm-2, surpassing those of commercial Pt/C (35 mV) and H-free Pd@Ru NBs (37 mV). Furthermore, an AEMWE device using PdH@Ru NBs as the cathode also achieves the current density of 1000 mA cm-2 at approximate to 1.80 V in 1.0 m KOH at 60 degrees C, with continuous operation for 50 h. The operando spectroscopic analysis and density functional theory calculations suggest that hydrogen insertion into the Pd@Ru NBs induces tensile strain on the Ru surface layer, altering the Pd/Ru electronic structure and weakening H adsorption, thereby enhancing the HER efficiency. The bamboo-like hollow structure features numerous active sites, which contribute to the optimization of electron/mass diffusion in the alkaline electrolyte. This work provides a potential high-efficiency cathodic electrocatalyst for industrial hydrogen production. Hollow PdH@Ru nanobamboos, synthesized via epitaxial growth and in-situ hydrogenation, enhance hydrogen evolution reaction efficiency due to lattice hydrogen-induced tensile strain on the Ru surface and the altered Pd/Ru electronic structure. An assembled anion-exchange membrane water electrolyzer with PdH@Ru nanobamboos as the cathode achieves 1000 mA cm-2 at similar to 1.80 V, demonstrating long-term stability and industrial viability. image