Heterojunction Engineering of NiC/NiPt Promoting Charge Remigration on Pt Site with Efficient Acid Hydrogen Evolution

Abstract

Alloying with transition metal can effectively reduce the content of Pt and improve the intrinsic hydrogen evolution activity of the catalyst. However, the problems of low stability and activity decay in the acidic environment of proton exchange membrane water electrolysis (PEMWE) have become difficulties in the development of such catalytic materials. In this work, the deep optimization of NiPt alloy was successfully achieved by high temperature carbonization treatment, and the acid-stable NiC/NiPt@C catalytic material was prepared. With a heterojunction structure, the NiC/NiPt@C exhibited an overpotential of 36.7 mV at -10 mA cm-2 with excellent stability. Density functional theory calculation and characterization revealed that the high performance was driven by the surface charge remigration of Pt site and the re-optimization of H adsorption strength. The performance (1000 mA cm-2 at 1.68 V, 80 ℃) and stability (1000 mA cm-2, 12 h) of the NiC/NiPt@C electrode were further verified in PEMWE cells, demonstrating its great potential for practical hydrogen production applications.