Electrocatalytic Hydrogen Oxidation by Defect-Enriched CuW Nanoalloy Featuring Hydrogen Spillover Effect

The development of efficient alkali-resistant non-noble metal electrocatalysts for hydrogen (H₂) oxidation reaction (HOR) is crucial for advancing the hydrogen economy. Recently, the hydrogen spillover effect has been proven to be one of the vital means to enhance the activity of the HOR catalyst. In this report, a facile and controllable electrodeposition strategy is proposed for synthesizing a tungsten (W)-doped copper (Cu) nanoalloy/WO₃ electrocatalyst with abundant metal-metal heterointerfaces to promote hydrogen spillover, i. e., the migration of ^*H from W/WO₃ sites to Cu substrates. CuW grown in situ on carbon paper (CP) demonstrates exceptional HOR performance (1.86 mA cm^-2 at 0.05 V vs. RHE) and remarkable stability in alkaline media. XAFS and density functional theory (DFT) calculations confirm that alloying W atoms into the Cu lattice induces electronic modulation, significantly boosting the adsorption, decomposition, and oxidation of H₂. The migration of ^*H from W/WO₃ sites to Cu sites via the hydrogen spillover effect has been validated by in-situ Fourier transform infrared (FT-IR) and Raman spectra. This study may open up a new path for designing high-efficiency HOR electrocatalysts from the perspective of appropriate hydrogen spillover channel design.