Mixed-Valence Ru Nanoparticles Anchored on N-rich Metal-Phthalocyanine/Graphene vdW Heterostructures for Hydrogen-Bond-Assisted Alkaline Hydrogen Evolution

Abstract

Hydrogen production via alkaline anion-exchange membrane H2O electrolysis (AEMWE) is constrained by sluggish hydrogen evolution reaction (HER) kinetics associated with H2O dissociation and hydroxyl management. Here, we report a pyrolysisfree Ru nanoparticles anchored on a two-dimensional metal-phthalocyanine/graphene vdW heterostructure (Ru@NiFe PPc) electrocatalyst for alkaline HER. The N-rich macrocyclic phthalocyanine framework and strong Ru-N coordination enable the uniform and stable dispersion of the mixed-valence Ru nanoparticles. The high-valence Ru centers accelerate interfacial H2O dissociation and hydroxyl transfer, whereas the Ru 0 sites facilitate *H desorption. Thus, Ru@NiFe PPc delivers exceptional HER performance with only 15 mV at 10 mA cm -2 , surpassing the best-performing Ru-based catalysts. As an AEMWE cathode, Ru@NiFe PPc delivers an industrial-scale current density of 2.0 A cm -2 at 2.09 V. In a hybrid electrolyzer coupling HER with low-potential 5-hydroxymethylfurfural oxidation, the system delivers 100 mA cm -2 at an ultralow cell voltage of 0.30 V. Theory calculations reveal that hydrogen-bond-assisted H2O adsorption on Ru nanoparticles, and the electronic coupling between Ru nanoparticles and phthalocyanine matrix weakens *OH binding, effectively lowering the overall HER barrier. This work elucidates the full alkaline HER pathway involving all key intermediates and opens a new avenue for the design of pyrolysis-free Ru-based HER catalysts.