Amorphous Cu–W Alloys as Stable and Efficient Electrocatalysts for Hydrogen Evolution
Xiying Jian, Wenbiao Zhang, Yaxiong Yang, Zhenglong Li, Hongge Pan, Qingsheng Gao, Huaijun Lin
Abstract
Cu and W are completely immiscible in equilibrium conditions, and neither of them is a good catalytic element for the electrochemical hydrogen evolution reaction (HER) due to their hydrogen adsorption Gibbs free energy (Δ G H ) being too positive or negative, respectively. However, the combination of Cu with W could potentially result in a moderate Δ G H . In this study, a series of binary amorphous Cu–W alloys are fabricated via a magnetron sputtering method. The optimal HER catalytic performance is demonstrated when the nominal component is Cu 50 W 50, showing an overpotential of only 65 mV at 10 mA cm –2 in 1 M KOH. Accordingly, density functional theory calculations show that the amorphous Cu 50 W 50 alloy has a close-to-zero Δ G H compared to the pure Cu and W metals, accounting for its HER activity. In addition, the amorphous Cu 50 W 50 alloy shows no obvious degradation at 100 mA cm –2 for 200 h, highlighting its long-term durability. This work provides a versatile strategy for the preparation of amorphous alloys with completely immiscible components and insights into the compositional design of nonprecious metal electrocatalysts for widespread applications.