Ultra-high activity methanol oxidation electrocatalyzed by a flexible integrated Pt–Zn array electrode

Abstract

Maximizing the utilization of Pt-based materials is a fundamental objective for practical direct methanol fuel cell technology at the commercial scale. In this study, a flexible integrated electrode composed of a class of Pt–Zn alloys grown in situ on carbon cloth (CC) are fabricated via a simple one-step electro-deposition approach. The 3D self-supporting configuration can efficiently accelerate rapid electron diffusion and expose more utilizable active sites, thus achieving highly active electrodes with strong anti-CO poisoning properties for catalyzing the methanol oxidation reaction (MOR). By regulate the input Pt/Zn molar ratio, the Pt₇Zn₁/CC electrode exhibits a superior mass activity of 2.48/5.89 A mg_Pt⁻¹ and specific activity of 310.36/905.99 mA cm⁻², which are 10.78/10.15 and 24.53/29.25 fold enhancements in comparison with those of commercial Pt/C in acid and alkaline media, respectively. Additionally, the anti-CO poisoning ability of Pt–Zn/CC was greatly enhanced by introducing the Zn. The mass activity loss of the Pt₇Zn₁/CC electrode in acid and alkaline media is only 91.65% and 84.33%, much lower than those of Pt/CC (97.30% and 92.89%) and commercial Pt/C (98.61% and 98.07%) after successive 10 h tests in acid and alkaline media, respectively. This work indicates a strategic design for significant improvements of efficient Pt-based alloy electrocatalysts in fuel cell applications.