Atomically dispersed ruthenium sites with electron-rich environments in intermetallic compounds for high-current-density hydrogen evolution

Abstract

Industrial electrocatalytic hydrogen production puts forward high requirements for catalysts. Compared to the traditional disordered alloy electrocatalysts, intermetallic compounds (IMCs) with ordered atomic arrangement exhibit higher mixing enthalpy and stronger atomic interactions, which greatly improves their catalytic performance and structural stability. Herein, we rationally design and precisely prepare ordered RuGa IMCs with the body-centered cubic structure on N-doped reduced graphene oxide supports (RuGa/N-rGO), which exhibit remarkable HER activities in both acidic and alkaline electrolytes. Notably, the obtained electrocatalyst requires extremely low overpotentials of 105 and 156 mV to deliver 500 and 1000 mA cm⁻², respectively, along with high stability over 100 hours continuously running at the overpotential of 100 mV in alkaline electrolyte. Experimental characterizations and theoretical simulations indicate that the Ru sites with electron-rich environments are isolated in RuGa/N-rGO, which significantly reduces the energy barrier of the rate-limiting step during the HER process. This work provides valuable insights into the atomic modulation of active sites for enhanced catalytic performance, paving a way for designing advanced noble metal-based electrocatalysts.