Phase-Stabilized Nickel-Molybdenum Electrocatalyst by Samarium Doping for Hydrogen Evolution in Alkaline Water Electrolysis.

Although the nickel-molybdenum electrocatalyst exhibits excellent activity in the alkaline hydrogen evolution reaction (HER), its stability is poor mainly due to molybdenum leaching. This work reports that doping samarium into nickel-molybdenum electrocatalyst effectively suppresses molybdenum leaching by forming a stable phase consisting of Sm, Mo, and O elements. The resulting electrode displays no noticeable activity degradation during the long-term testing (> 850 h) under a current density of 500 mA cm in 1 м KOH This enhanced stability is ascribed to the formation of a robust phase within the HER potential windows in alkaline electrolytes, as evidenced by the Pourbaix diagram.

Hydrogen Evolution Reaction on Single-Atom Pt Doped in Ni Matrix under Strong Alkaline Condition.

Pt catalyst has been considered as the state-of-the-art catalyst for hydrogen evolution reaction (HER) under acid condition. However, its catalytic kinetics under alkaline conditions is not well-understood. Herein, we report a Ni-Pt(SAs) (SAs = single atoms) catalyst with Pt atomically dispersed in a Ni matrix, and it possesses an impressive HER performance with an overpotential as low as 210 mV at 500 mA cm in strong alkaline electrolyte (7 M KOH), which is much higher than Pt nanoparticle-modified Ni catalyst (Ni-Pt(NPs)).