Heterogeneous Support Effects for Enhanced Performance in Anion Exchange Membrane Water Electrolysis

Anion exchange membrane water electrolyzer (AEMWE) is promising for clean hydrogen production, yet it encounters challenges such as inefficient oxygen evolution reaction (OER) kinetics and instability under industrial-relevant current densities. Exploring Ru-based materials with metal-support interaction (MSI) represents a promising strategy for developing exceptional performance of electrocatalytic water splitting. Herein, a heterojunction-supported Ru single-atom catalyst (Ru-NCO/rGO) is reported with an ultrahigh Ru loading of 10.76 wt.% and RuO₃ configuration. The NiCo₂O₄/rGO enhances the MSI and tunes the electronic structure of Ru sites, resulting in highly efficient and stable alkaline OER performance. The Ru-NCO/rGO exhibits a low overpotential of 219 mV at 10 mA cm⁻², superior to most currently reported Ru-based OER catalysts. Remarkably, the AEMWE using Ru-NCO/rGO requires only 1.89 V to deliver 1.0 A cm⁻², while maintaining stable operation for 200 h at 500 mA cm⁻². Density functional theory (DFT) reveals that the heterojunction supports can optimize the charge distribution of Ru sites, strengthen the MSI, thereby reducing the RDS energy barrier while enhancing catalytic performance.