Designing Ru–B–Cr Moieties to Activate the Ru Site for Acidic Water Electrolysis under Industrial-Level Current Density

Developing highly efficient non-iridium-based active sites for acidic water splitting is still a huge challenge. Herein, unique Ru-B-Cr moieties have been constructed in RuO₂ nanofibers (NFs) to activate Ru sites for water electrolysis, which overcomes the bottleneck of RuO₂-based catalysts usually possessing low activity for the hydrogen evolution reaction (HER) and poor stability for the oxygen evolution reaction (OER). The fabricated Cr, B-doped RuO₂ NFs exhibit low overpotentials of 205 and 379 mV for acidic HER and OER at 1 A cm^-2 with outstanding stability lasting 1000 and 188 h, respectively. The assembled acidic electrolyzer also possesses great hydrogen production efficiency and durability at a high current density. Experimental and theoretical explorations reveal that the formation of Ru-B-Cr moieties effectively optimizes the atomic configurations and modulates the adsorption/desorption free energy of reaction intermediates to achieve exceptional HER and OER performance.