Re-Dispersion of Platinum From CNTs Substrate to α-MoC1-x to Boost the Hydrogen Evolution Reaction.

Abstract

Developing high-performance electrocatalysts toward hydrogen evolution reaction (HER) is important for clean and sustainable hydrogen energy, yet still challenging. Herein, an α-MoC1-x induced redispersing strategy to construct a superior HER electrocatalyst (Pt/CNTs-N+α-MoC1-x ) by mechanical mixing of α-MoC1-x with Pt/CNTs-N followed by thermal reduction is reported. It is found that thermo-activation treatment enables partial Pt atoms to redisperse on α-MoC1-x substrate from carbon nanotubes, which creates dual active interfaces of Pt species dispersed over carbon nanotubes and α-MoC1-x . Benefiting from the strong electronic interaction between the Pt atom and α-MoC1-x , the utilization efficiency of the Pt atom and the zero-valence state of Pt is evidently enhanced. Consequently, Pt/CNTs-N+α-MoC1-x catalyst exhibits excellent HER activity with low overpotentials of 17 and 34 mV to achieve a current density of 10 mA cm-2 in acidic and alkaline electrolytes, respectively. Density functional theory calculations further reveal that the synergistic effect between Pt and α-MoC1-x makes it accessible for the dissociation of water molecules and subsequent desorption of hydrogen atoms. This work reveals the crucial roles of α-MoC1-x additives, providing practical solutions to enhance platinum dispersion, and thereby enhance the catalytic activity in HER.