Self-supported Pt nanoflakes-doped amorphous Ni(OH)2 on Ni foam composite electrode for efficient and stable methanol oxidation

Abstract

Direct methanol fuel cells (DMFCs) are promising power sources for automobiles and portable electronic devices. Its commercialization depends on the anodes with high activity, low Pt content, and especially high stability towards methanol oxidation. Herein, a self-supported Pt nanoflakes and amorphous Ni(OH)2 on nickel foam composite electrode (Pt-doped Ni(OH)2, Pt content: 1.5 wt%) with rich defects was fabricated via a facile and low cost galvanic deposition method. This composite anode exhibits enhanced activity and stability for methanol oxidation in alkaline media, which mainly come from the synergistic effects between Pt nanoflakes and amorphous Ni(OH)2 on Ni foam substrate and defect engineering. During a typical methanol oxidation process over Pt-doped Ni(OH)2: Pt nanoflakes act as the active sites; amorphous Ni(OH)2 promotes the poison removal; Ni foam provides high electric conductivity and large area; defects sites contribute to the enhanced activity and stability. This work suggests that this self-supported and defect-enriched Pt-doped Ni(OH)2 composite catalyst is an alternative to commercial Pt-based electrocatalyst for low temperature DMFCs.