Degradation mechanism of self-supported high-entropy metallic glass cathode in fluctuating renewable energy-powered acid water electrolysis

The degradation behavior and hydrogen evolution reaction (HER) performance of nano-porous PdPtCuNiP (NP-PdPtCuNiP) high entropy metallic glass in 65℃ 0.5 mol L⁻¹ H₂SO₄ electrolyte was investigated. For electrolytic system shutdown condition, the corrosion effect would lead the dissolution of Ni, Cu and P from NP-PdPtCuNiP surface, and form a Pd-Pt binary alloy catalytic surface. Meanwhile, the input power fluctuation resulting in incomplete cathodic protection of the cathode. The corrosion on cathode surface caused the surface constituent and morphology changed, and the surface condition is affected by power frequency. Finally, an in-situ repair strategy for degraded cathode is proposed.