Ultra-rapid hydrogen evolution reaction kinetics over CeO2@PtCu coaxial nanocables

Abstract

Pt-based catalysts with robust performance towards hydrogen evolution reaction in acidic media are urgently needed. The thin-layer structure can expose most active sites on surface and tune electronic structures of Pt-based catalysts. However, establishing the Pt thin-layer on support is challenging due to poor lattice compatibility and step-edge barriers to interlayer transport, which often results in roughening or sintering. Herein, we first coat Cu on CeO₂ nanowire using sol-gel method and then construct a PtCu thin-layer by a “glue” effect, achieving a coaxial nanocable structure CeO₂ NW@PtCu catalyst. Benefiting from the PtCu thin-layer structure and large metal-support interface, the electron density at Fermi level increases, and the charge transfer is facilitated, leading to a stronger metal-support interaction and a lower energy barrier for adsorption/desorption of H*. As expected, the catalyst exhibits an overpotential as low as 7 mV at a current density of 10 mA cm⁻², and a mass activity of 2.9 A mg⁻¹_Pt, which is 72.5 times that of commercial Pt/C. Even after 2000 CV cycles, the structure and activity remain unchanged. This work demonstrates a promising strategy for improving the utilization efficiency and stability of Pt in HER and other catalytic reactions.