Despite its cost‐effectiveness for the hydrogen evolution reaction (HER), ruthenium faces commercialization challenges due to oxidative instability. Here, we designed a Ru–WO x /C catalyst with an amorphous WO x overlayer that protects Ru from oxidation and induces hydrogen spillover. TEM and energy‐dispersive X‐ray spectroscopy (EDS) confirmed that Ru nanoparticles are uniformly coated by an amorphous WO x overlayer. X‐ray photoelectron spectroscopy (XPS) revealed the coexistence of W 6+ /W 5+ species and a negative shift in the Ru 3p binding energy, evidencing the formation of WO x and heterojunction. Ru–WO x /C required only 56 mV to reach 10 mA cm −2 and maintained stable operation for 80 h at 100 mA cm −2 . The remarkable activity and stability of the developed Ru–WO x /C catalyst originate from hydrogen spillover. This result is supported by potassium thiocyanate (KSCN) poisoning and H/D kinetic isotope effect (KIE) experiments, which confirmed hydrogen migration from WO x to Ru. When applied as a cathode in a proton exchange membrane water electrolyzer (PEMWE), Ru–WO x /C achieved current densities of 0.5, 1.0, and 2.0 A cm −2 at 1.66, 1.85, and 2.10 V, respectively. It also sustained stable operation for 24 h at 1 A cm −2 with nearly 100% Faradaic efficiency. These results show that integrating an amorphous WO x overlayer with Ru nanoparticles is a practical approach to design a durable and efficient cathode for proton exchange membrane water electrolysis.
Jung et al. (Thu,) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: