Title : Nanometer-thin DALP- Pt electrocatalysts with ultralow platinum loading for efficient hydrogen evolution reaction
Abstract:
Hydrogen production through proton exchange membrane (PEM) water electrolysis requires highly active and stable electrocatalysts while minimizing noble metal consumption. Here, we present Direct Atomic Layer Processing (DALP®) as a rapid, maskless, and material-efficient manufacturing platform for fabricating ultrathin Pt electrocatalysts with precise nanoscale thickness control for the hydrogen evolution reaction (HER).
Using DALP®, Pt thin films with thicknesses ranging from 2–50 nm were directly fabricated on glassy carbon substrates within a single deposition process under atmospheric conditions. The resulting Pt loadings ranged from approximately 0.004–0.10 mg cm?², significantly lower than conventional PEM electrolyzer cathodes. Electrochemical measurements in acidic media (0.5 M H?SO?) demonstrated strong thickness-dependent HER activity. Films in the 10–30 nm range exhibited near-bulk Pt catalytic behavior, achieving current densities of 10 mA cm?² at overpotentials of approximately 45–50 mV with Tafel slopes of 30–40 mV dec?¹. The 30 nm DALP-Pt film showed the highest electrochemically active surface area (ECSA), lowest charge-transfer resistance, and exchange current density of 0.5–0.6 mA cm?², indicating optimal Pt utilization.
Morphological and electrochemical analyses revealed a transition from discontinuous Pt islands at 2 nm to continuous nanostructured films at intermediate thicknesses, followed by grain coarsening and reduced utilization at 50 nm. Notably, increasing Pt thickness beyond 30 nm produced minimal improvements in HER performance, demonstrating that DALP enables substantial reduction in Pt usage without compromising catalytic activity. Stability testing further confirmed excellent electrochemical durability over prolonged cycling.
These findings establish DALP® as a powerful platform for high-throughput fabrication and optimization of low-loading electrocatalysts with atomic-scale precision. The demonstrated combination of ultralow Pt loading, near-bulk HER kinetics, and scalable direct-write manufacturing offers a promising pathway toward cost-effective hydrogen production technologies and accelerated catalyst discovery for clean energy applications.
