Tailored Electrodeposition for Scalable Fabrication of Uniform and High-Efficiency Large-Area Electrodes for PEM Water Electrolysis

초록

Water electrolysis is a promising route for large-scale hydrogen production, offering high-purity output, CO2-free emissions, and compatibility with renewable energy integration. Among various fabrication techniques, electrodeposition provides a cost-effective, tunable, and binder-free method for producing high-performance electrodes. However, achieving consistent catalyst properties across large electrode areas remains a major challenge in scaling up electrochemical devices such as proton exchange membrane water electrolyzers (PEMWEs). This study presents a systematic electrodeposition approach for fabricating large-area Cu–Ni–Mo alloy catalysts with homogeneous composition and electrochemical performance across the electrode surface, guided by a previously optimized small-area reference. A custom-designed deposition cell enabled independent control of deposition parameters, and the effects of each parameter on catalyst composition, morphology, and hydrogen evolution reaction (HER) activity were thoroughly evaluated. As the electrode area increased, structural modifications to the deposition cell and electrode configurations required adjusting the deposition potential to maintain equivalent deposition conditions. The working–reference electrode distance was identified as a critical parameter that significantly influenced the actual deposition potential and resulting catalyst properties, while the working–counter electrode distance affected deposition uniformity through changes in ion transport dynamics. Under optimized conditions, a 10.2 cm2 electrode was fabricated and evaluated through subdivided PEMWE tests, yielding consistent performance (2.00 to 2.03 Vcell at 2 A cm−2) with only minor deviation from the reference catalyst. Scaling up further to 50 cm2 yielded an average HER overpotential of 18.3 mV at −10  mA cm−2 and maintained excellent uniformity across the electrode. These findings offer a practical and adaptable methodology for fabricating large-area alloy electrodes with reproducible performance, advancing the scalable deployment of multicomponent catalysts for PEMWE.

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