Self-standing nanoporous NiPd bimetallic electrocatalysts with ultra-low Pd loading for efficient hydrogen evolution reaction

Abstract

The decrease of noble metal content is an efficient way to achieve commercial electrocatalysts with a low fabrication cost. However, it is difficult to balance between a stable bimetallic structure and an ultra-low loading of noble metals in alloys. In the present work, a highly efficient nanoporous NiPd/metallic glass (np-NiPd/MG) electrocatalyst was synthesized by combining dealloying and galvanic replacement reaction to minimize the Pd utilization rate in alloys. Sandwich-like structures with nanoporous layers on the surface of both sides and inner metal glass matrix were observed, which exhibited a remarkable catalytic activity for hydrogen evolution reaction with a low overpotential. The np-NiPd/MG showed a rather low Pd loading (14 Pd μg cm−2). The excellent catalytic properties are endowed by abundant active sites, improved intrinsic activity, and fast species and electrons transport. This work provides a promising strategy to fabricate highly efficient self-standing electrocatalysts for industrial hydrogen production.