Defect-Rich RuCu Multilayered Nanosheets for Effective Alkaline Hydrogen Electrocatalysis

The development of highly active and durable catalysts for the alkaline hydrogen oxidation reaction (HOR) and hydrogen evolution reaction (HER) is crucial for advancing the hydrogen energy applications. Herein, we present 2D defect-rich RuCu multilayered nanosheets (RuCu MNSs) as efficient catalysts for alkaline HOR/HER. Experimental characterizations and theoretical calculations reveal that the defect-rich structure modulate the adsorption of key intermediates (*H and *OH), thereby enhancing catalytic activity. Notably, the RuCu MNSs/C catalyst exhibits a superior mass activity of 4.91 A mg^-1 at 50 mV vs. the reversible hydrogen electrode (RHE), significantly outperforming Ru MNSs/C (0.56 A mg^-1) and commercial Pt/C (0.32 A mg^-1). Strikingly, RuCu MNSs/C also demonstrated excellent CO tolerance, the current density of RuCu MNSs/C decreases by only 20.12% after continuous operation for 3000 s in a 0.1 M KOH solution saturated with 100 ppm CO/H₂. Furthermore, RuCu MNSs/C requires a low overpotential of merely 22.42 mV to achieve a current density of 10 mA cm^-2 for the HER. This work provides a feasible strategy for designing high-performance Pt-free electrocatalysts.