Mesoporous PtRhCu Nanoalloy as the Electrocatalyst for the Enhanced Hydrogen Evolution Reaction

Developing efficient and stable electrocatalysts for the hydrogen evolution reaction (HER) is very important for sustainable hydrogen production, but it is still a huge challenge. In this study, the preparation of mesoporous PtRhCu nanoalloys via a soft-template method is reported. By simply adjusting the molar ratios between Pt, Rh, and Cu, mesoporous PtRhCu nanoalloys with different particle sizes and surface areas are obtained. Comparable experiments indicate that the molar ratio between different metals of PtRhCu nanoalloys has a close relationship with the electrochemical surface area and charge transfer impedance, which finally affect the HER performance. In addition, the mesoporous structure of PtRhCu nanoalloys offers the electrocatalyst large numbers of accessible active sites and gas diffusion channels. Due to the synergistic effects of the alloy and mesoporous structure, consequently, the mesoporous PtRhCu nanoalloy with optimized composition shows superior HER activity in an alkaline environment, with an ultralow overpotential of 23 mV at a current density of 10 mA cm–2 when the mass loading is only 0.02 mg cm–2, surpassing the commercial Pt/C (32 mV). Meanwhile, the optimal mesoporous PtRhCu nanoalloy also shows more robust stability than commercial Pt/C.