Cost-effective and mass-producible Co-sputtered Pt3Ni alloy electrocatalyst on CNT sheet for high-performance ultra-low Pt proton exchange membrane fuel cells

초록

In this study, highly active Pt3Ni and Pt-skin structured catalysts were fabricated by sputtering onto acid-treated carbon nanotube (CNT) sheets, forming Alloy/CNT and Pt-skin/CNT configurations. Precise control of the target shutter enabled regulation of Pt-Ni composition and deposition sequence, producing distinct nanostructures. The Alloy/CNT catalyst with a uniform Pt3Ni composition exhibited a 31.4 % higher power density, 41.5 % higher mass activity, 109.1 % larger electrochemically active surface area, and 51.1 % lower charge transfer resistance than commercial Pt/C at an ultra-low loading of 0.05 mgPt cm-2. These enhancements stem from alloy-induced lattice contraction and a downshifted Pt d-band center with reduced binding energy, decreasing oxygen intermediate adsorption energy and improving ORR kinetics. Furthermore, by integrating an acid-treated CNT sheet catalyst support with sputtering catalyst deposition, this work presents a binder-free electrode architecture that enables efficient triple-phase boundary formation. This approach offers a promising electrode design strategy for developing high-performance, low-Pt-loading catalysts.

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