Fabrication of multimetallic nanocatalysts with controllable composition remains a challenge for the development of low-cost electrocatalysts, and incorporating metal-based catalysts into active carbon nanoarchitectures represents an emerging strategy to improve the catalytic performance of electrocatalysts. Herein, a facile method developed for Pd nanoparticle (NP)-based multimetallic alloys incorporated on polypyrrole (Ppy) nanofibers by in situ nucleation and growth of NPs using colloidal radiolytic technique is described. Electrochemical measurement suggests that the as-prepared catalysts demonstrate dramatically enhanced electrocatalytic activity for ethanol oxidation in alkaline medium. The ultrasmall Pd₃₀Pt₂₉Au₄₁/Ppy nanohybrids (∼8 nm) exhibit excellent electrocatalytic activity, which is ∼5.5 times higher than that of its monometallic counterparts (12 A/mg Pd, 5 times higher activity compared to that of Pd/C catalyst). Most importantly, the ternary nanocatalyst shows no obvious change in chemical structure and long-term stability, reflected in the 2% loss in forward current density during 1000 cycles. The superior catalytic activity and durability of the nanohybrids have been achieved due to the formation of Pt–Pd–Au heterojunctions with cooperative action of the three metals in the alloy composition, and the strong interactions between the Ppy nanofiber support with the metal NPs. The facile synthetic approach provides a new generation of polymer-supported metal alloy hybrid nanostructures as potential electrocatalysts with superior catalytic activity for fuel cell applications.

中文翻译：

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嵌入聚合物中的高活性多金属钯纳米合金作为乙醇电氧化的阳极催化剂

具有可控组成的多金属纳米催化剂的制造对于低成本电催化剂的发展仍然是一个挑战，并且将金属基催化剂掺入活性炭纳米结构中是改善电催化剂催化性能的新兴策略。在此，描述了一种通过使用胶体放射分解技术通过NP的原位成核和生长而为掺入聚吡咯（Ppy）纳米纤维上的基于Pd纳米颗粒（NP）的多金属合金开发的简便方法。电化学测量表明，所制备的催化剂在碱性介质中显示出对乙醇氧化的显着增强的电催化活性。超小型Pd ₃₀ Pt ₂₉ Au ₄₁/ Ppy纳米杂化物（〜8 nm）表现出优异的电催化活性，比其单金属对应物的电催化活性高约5.5倍（12 A / mg Pd，比Pd / C催化剂高5倍）。最重要的是，三元纳米催化剂在化学结构和长期稳定性方面没有显示出明显的变化，这反映出在1000次循环中正向电流密度损失了2％。由于在合金成分中三种金属的协同作用下形成的Pt-Pd-Au异质结以及Ppy纳米纤维载体与金属NP之间的强相互作用，从而实现了纳米杂化物的优异催化活性和耐久性。