Multifunctional Ultrathin PdxCu1鈥搙 and Pt鈭糚dxCu1鈥搙 One-Dimensional Nanowire Motifs for Various Small Molecule Oxidation Reactions

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• 作者：Haiqing Liu ; Radoslav R. Adzic ; Stanislaus S. Wong
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：December 2, 2015
• 年：2015
• 卷：7
• 期：47
• 页码：26145-26157
• 全文大小：669K
• ISSN：1944-8252

文摘

Developing novel electrocatalysts for small molecule oxidation processes, including formic acid oxidation (FAOR), methanol oxidation reaction (MOR), and ethanol oxidation reaction (EOR), denoting the key anodic reactions for their respective fuel cell configurations, is a significant and relevant theme of recent efforts in the field. Herein, in this report, we demonstrated a concerted effort to couple and combine the benefits of small size, anisotropic morphology, and tunable chemical composition in order to devise a novel 鈥渇amily鈥?of functional architectures. In particular, we have fabricated not only ultrathin 1-D Pd_1鈥?i>xCu_x alloys but also Pt-coated Pd_1鈥?i>xCu_x (i.e., Pt鈭糚d_1鈥?i>xCu_x; herein the 鈭?indicates an intimate association, but not necessarily actual bond formation, between the inner bimetallic core and the Pt outer shell) core鈥搒hell hierarchical nanostructures with readily tunable chemical compositions by utilizing a facile, surfactant-based, wet chemical synthesis coupled with a Cu underpotential deposition technique. Our main finding is that our series of as-prepared nanowires are functionally flexible. More precisely, we demonstrate that various examples within this 鈥渇amily鈥?of structural motifs can be tailored for exceptional activity with all 3 of these important electrocatalytic reactions. In particular, we note that our series of Pd_1鈥?i>xCu_x nanowires all exhibit enhanced FAOR activities as compared with not only analogous Pd ultrathin nanowires but also commercial Pt and Pd standards, with Pd₉Cu representing the 鈥渙ptimal鈥?composition. Moreover, our group of Pt鈭糚d_1鈥?i>xCu_x nanowires consistently outperformed not only commercial Pt NPs but also ultrathin Pt nanowires by several fold orders of magnitude for both the MOR and EOR reactions in alkaline media. The variation of the MOR and EOR performance with the chemical composition of our ultrathin Pt鈭糚d_1鈥?i>xCu_x nanowires was also discussed.