Anchoring platinum clusters on lamellar MXene for efficient acidic hydrogen evolution reaction

Hydrogen energy, as a clean and renewable alternative to fossil fuels, requires efficient electrocatalysts for sustainable hydrogen production via the hydrogen evolution reaction (HER). Platinum-based catalysts exhibit superior HER activity but face challenges of high cost, instability, and aggregation under acidic conditions. MXenes, two-dimensional materials with high conductivity and tunable surface chemistry, offer promising support platforms to enhance platinum utilization. Here, we report the design of highly active and stable HER catalysts by anchoring sub-nanometer platinum clusters onto lamellar Ti 3 C 2 and Nb 2 C MXenes via a cluster beam deposition technique. The optimized Pt/Ti 3 C 2 catalyst achieves a low overpotential of 67 mV at 10 mA cm −2 in acidic media, outperforming Pt/Nb 2 C (72 mV), pure Pt clusters (79 mV), and commercial Pt/C (82 mV). This enhancement arises from Ti 3 C 2 's larger surface area, which stabilizes Pt clusters, prevents aggregation, and facilitates interfacial electron transfer. The Pt/Ti 3 C 2 heterojunction also demonstrates a Tafel slope of 26.3 mV dec −1 , indicating rapid Volmer-Tafel kinetics, and retains 95 % activity after 5 h of operation. Compared to prior Pt/MXene systems, this work highlights the critical role of MXene surface functionality and Pt cluster dispersion in optimizing HER performance. By reducing platinum loading while maintaining high efficiency, this strategy advances the development of cost-effective electrocatalysts for scalable green hydrogen production. Our findings provide a blueprint for engineering MXene-supported metal clusters to address energy and sustainability challenges.