Nitrogen-Containing-Defect-Site-Assisted H2O Adsorption and Dissociation on Crystalline Ru Nanoclusters by Quasi-Hydrogen Bonds Boosts Alkaline Hydrogen Evolution Reaction

In the pursuit of advancing electrolytic water hydrogen production technology, the development of a cost-effective alkaline hydrogen evolution reaction (HER) catalyst, characterized by high activity and stability, holds paramount importance. In this context, we synthesized a crystalline Ru nanoclusters (NCs) catalyst supported on a three-dimensional layered nitrogen-doped carbon (3DLNC) material through a straightforward impregnation pyrolysis method. The optimized Ru/3DLNC-500 catalyst demonstrated remarkable electrocatalytic performance, featuring an exceptionally low overpotential of 18.5 mV at 10 mA cm–2, an extraordinarily high mass activity (10-fold greater than a 20% platinum carbon catalyst), and commendable stability. Insights gained from in situ Raman characterization and theoretical calculations lead to two noteworthy conclusions. First, the alkaline HER activity of crystalline Ru NCs is attributed to their heightened water adsorption capacity and accelerated hydrogen desorption rate. Second, under reaction conditions, the nitrogen-containing defect sites on the surface of 3DLNC serve as additional sites for water molecule adsorption by forming quasi-hydrogen bonds, thereby facilitating the alkaline HER by enhancing the adsorption and dissociation capabilities of water molecules on the catalyst.