Electrodeposited low-Pt core–shell nanoparticles as oxygen reduction electrocatalysts for PEMFCs

Over the past two decades, polymer electrolyte membrane fuel cells (PEMFCs) have made remarkable progress in performance and durability; however, the high cost associated with platinum-based cathodes remains a major barrier to large-scale deployment. In this context, the development of scalable, platinum-efficient oxygen reduction reaction (ORR) electrocatalysts is a critical challenge.

In this work, a scalable electrodeposition approach for the fabrication of nanostructured core–shell (Ni-W)@Pt electrocatalysts with ultra-low platinum loading for PEMFC cathodes is presented. Using pulse electrodeposition, Pt shells were directly deposited onto non-noble Ni-W cores, enabling precise control over nucleation, particle size, surface coverage, and shell morphology while grown directly on the gas diffusion layer. Platinum loadings as low as 0.013 mg cm⁻² were achieved while maintaining homogeneous catalyst distribution.

The catalysts were comprehensively characterized by means of FE-SEM, HR-TEM, and ICP-MS, and their ORR activity was evaluated in acidic media. The optimized (Ni-W)@Pt catalysts exhibited high open-circuit potentials (≥ 0.95–1.0 V vs. RHE) and outstanding mass activities, reaching ~10 A g⁻¹ at 0.9 V, despite the drastically reduced precious metal content. Complementary machine-learned force field simulations provided insight into strain effects arising from the Ni-W core on the Pt shell, supporting the experimentally observed activity performance. Additionally, the influence of Pt loading and mesoporous shell structures on electrode durability is investigated.

The results demonstrate that electrodeposition is an industrially relevant and versatile strategy for producing high-performance, low-Pt PEMFC cathodes, offering a promising pathway toward cost-effective and sustainable fuel cell technologies.

Acknowledgments

Funded by the European Union under the GA number 101058076-NICKEFFECT project. The views and opinions expressed, however, arethose of the author(s) only and do not necessarily reflect those of the European Union or European Health and Digital Executive Agency (HaDEA). Neither the European Union nor HaDEA can be held responsible for them.