Balance between Activity and Stability of Single Metal and Intermetallic Compounds for Electrocatalytic Hydrogen Evolution Reaction

Combining Re (strongbonding), Ru (HER active), and Zr metal(corrosion-resistant) grants ternary intermetallic compound ZrRe1.75Ru025, exhibiting excellent HER activity andstability in acidic and alkaline electrolytes Thehigher population of the antibonding state around the Fermilevel will result in better activity yet lower stability of HER (Revs Ru metal). There seems to be a limitation or balance for usinga single metal since the bonding scheme of a single metal is relativelysimple. Combining Re (strong bonding), Ru (HER active), and Zr metal(corrosion-resistant) grants ternary intermetallic compound ZrRe1.75Ru025, exhibiting excellent HER activity andstability in acidic and alkaline electrolytes. The overpotential ata current density of 10 mA/cm(2) (& eta;(10)) forZrRe(1.75)Ru(025) is much lower compared to thatof ZrRe2. Although the HER activity of ZrRe1.75Ru025 is not comparable to that of ZrRu2, itdemonstrates outstanding HER stability, while the current densityof ZrRu2 is over ca. 16% after 6 h. Thissuggests that intermetallic compounds can break the constraint betweenactivity and stability in a single metal for HER, which may be appliedin other fields as well.