Three-dimensional bimetallic Pd–Cu nanodendrites with superior electrochemical performance for oxygen reduction reaction

Efficient, cost-effective and stable catalysts for cathodic oxygen reduction reaction (ORR) are highly desirable for both chemical and microbial fuel cells. Nano-materials with three-dimensional (3D) porous materials are gaining popularity recently, because of their large surface areas and numerous active sites. In this work, we prepare a unique self-supporting Pd–Cu bimetallic catalyst with 3D porous structure using a facile double-template fabrication process and evaluate its performance as an ORR catalyst. This catalyst is found to possess an electrochemically active surface area of 80.2 m2/gPd, a peak current of 17.4 mA/cm2 and an unusual limiting current density of 12 mA/cm2. Meanwhile, the fabricated bimetallic catalyst displays a better long-term stability than the state-of-the-art Pt/C catalyst. This work provides useful information on the facile preparation of cost-effective cathodic catalysts for chemical or microbial fuel cells in a controllable way.

► A 3-dimensional nano Cu–Pd catalyst is prepared via an electrodeposition method using H2 bubbles as a dynamic template.
► The coral foam is used as a sacrificing template to fabricate a Cu–Pd bimetallic catalyst via spontaneous galvanic replacement.
► The electrochemical activity for ORR of the catalyst is remarkably high.
► The catalyst can keep its high-output state much long.