Boron Carbide Supported Ultra‐Small Ruthenium Nanoparticles with High‐Performance for Hydrogen and Chlor‐Alkali Co‐Production

ABSTRACT Ruthenium (Ru) is a promising electrocatalyst for hydrogen and chlor‐alkali co‐production, but suffers from poor water adsorption and hydrogen desorption. To enhance its hydrogen evolution reaction (HER) performance, this study employs density functional theory (DFT) to explore how non‐metallic supports (B, C, N) modulate the electronic structure of Ru via metal‐support interactions (MSIs). Results reveal B ₄ C as the optimal support, with 1.56 electrons transferred from Ru ₁₃ to B ₄ C, shifting the Ru d‐band center closer to the Fermi level and synergistically optimizing the adsorption of HER intermediates. The synthesized N‐doped carbon‐coated Ru/B ₄ C catalyst (Ru/B ₄ C@NC) exhibits outstanding alkaline HER activity, achieving overpotentials of only 5 mV at 10 mA cm ⁻² and 361 mV at 1 A cm ⁻² , along with stability over 500 h. Under chlor‐alkali conditions, Ru/B ₄ C@NC also maintains high HER activity with overpotentials of 5 and 99 mV at 10 and 500 mA cm ⁻² and long‐term stability for 300 h. A hybrid electrolysis cell with Ru/B ₄ C@NC (−) //RuO ₂ /IrO ₂ ‐coated Ti mesh (+) achieves a record low voltage of 2.33 V at 10 mA cm ⁻² with long‐term stability for 100 h. This work provides valuable insights for designing advanced Ru‐based catalysts for integrated hydrogen and chlor‐alkali production.