A molecular strategy to Ni45Pt55@NC nanoparticles as efficient and robust Electrocatalyst for hydrogen evolution reaction

Abstract

Metallopolymers have garnered enormously attention as one of the most promising functional materials in recent years. The earth-abundant transition metal alloyed Pt-based nanoparticles (NPs) as pyrolyzed from metallopolymers show appealing prospects in decreasing the Pt-loading amount and enhancing the long-term stability of electrocatalysts. Herein, we reported a molecular strategy for preparation of efficient electrocatalyst of N-doped Ni45Pt55@NC NPs by employing a new-designed metallopolymer P-NiPt as precursor. The morphology, size, and composition of the resultant Ni45Pt55@NC NPs were fully characterized. The results of electrocatalysis experiments indicate that the resultant Ni45Pt55@NC NPs possess outstanding HER electrocatalytic activity with a low Pt-loading amount of 8.35 wt% in 0.5 M H2SO4 electrolyte. The calculated mass activity of Ni45Pt55@NC NPs at the overpotential of 30 mV is 0.232 A/mgPt, which was twice of that of commercial Pt/C (0.085 A/mgPt). In the meantime, the Ni45Pt55@NC NPs display excellent long-term catalytic stability in acid media. We found that such improved HER catalytic activity and stability with low Pt-loading amount could be mainly credited to the interaction between Ni and Pt atoms by the DFT calculation modeling. In a word, this work demonstrates a promising approach to develop efficient and robust electrocatalysts with controllable Pt-loading amount via the molecular strategy.