Intermetallic CuZr Clusters Anchored on Hierarchical Nanoporous Copper as Efficient Catalysts for Hydrogen Evolution Reaction.

Designing highly active and robust platinum-free electrocatalysts for hydrogen evolution reaction is vital for large-scale and efficient production of hydrogen through electrochemical water splitting. Here, we report nonprecious intermetallic CuZr clusters that are in situ anchored on hierarchical nanoporous copper (NP Cu/CuZr) for efficient hydrogen evolution in alkaline medium. By virtue of hydroxygenated zirconium atoms activating their nearby Cu-Cu bridge sites with appropriate hydrogen-binding energy, the CuZr clusters have a high electrocatalytic activity toward the hydrogen evolution reaction. Associated with unique architecture featured with steady and bicontinuous nanoporous copper skeleton that facilitates electron transfer and electrolyte accessibility, the self-supported monolithic NP Cu/CuZr electrodes boost violent hydrogen gas release, realizing ultrahigh current density of 500 mA cm at a low potential of -280 mV versus reversible hydrogen electrode, with exceptional stability in 1 M KOH solution. The electrochemical properties outperform those of state-of-the-art nonprecious metal electrocatalysts and make them promising candidates as electrodes in water splitting devices.