Electron-networking Cu single atom-spurred Ru clusters for anion exchange membrane water electrolysis

A unique Ru/Cu@CN featuring Cu single atoms-spurred Ru clusters on a N-modified carbon support was synthesized. • The hydrogen evolution reaction performance of Ru/Cu@CN was precisely regulated via Cu single-atom electronic networks. • The Ru/Cu@CN-based AEMWE achieves a high current density of 5.4 A cm −2 @2.0 V in 1 M KOH@80 °C. • The Ru/Cu@CN-based AEMWE operates stably at 2 A cm −2 for over 600 h without a significant voltage decay. Developing cost-effective, highly efficient, and durable hydrogen evolution reaction (HER) catalysts is critical for the commercialization of anion exchange membrane water electrolysis (AEMWE). However, this remains a significant challenge due to the over-reliance on platinum-based catalysts, especially when operating at ampere-level current densities. Here, we present a Cu electron-networking strategy to create Cu single atom-stabilized Ru clusters on an N-modified carbon support (Ru/Cu@CN), in which bridged Cu sites can efficiently stabilize Ru clusters and promote uniform dispersion of high-density Ru through strong metal-support interactions while weakening the overly strong Ru H bond via Ru Cu electron transfer, thereby substantially enhancing the HER activity and stability of Ru/Cu@CN. As a result, the Ru/Cu@CN-based AEMWE achieves exceptional current densities of 5.4 A cm −2 at 2.0 V and 3 A cm −2 at 1.79 V in 1 M KOH with a low Ru loading of 0.3 mg cm −2 , fulfilling the US Department of Energy (DOE) 2025 target (3 A cm −2 at <1.8 V) and competing favorably with the state of the art. Moreover, we demonstrate that the Ru/Cu@CN-based AEMWE can be operated at a high current density of 2 A cm −2 for over 600 h without a significant cell voltage decay Ru/Cu@CN thus represents a promising HER catalyst for practical AEMWE applications.