Wavy PtCu alloy nanowire networks with abundant surface defects enhanced oxygen reduction reaction
Wavy PtCu alloy nanowire networks with abundant surface defects enhanced oxygen reduction reaction
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具有丰富表面缺陷的波状 PtCu 合金纳米线网络增强了氧还原反应
DOI：
10.1007/s12274-019-2511-8
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发表时间：
2019-11-01
期刊：
影响因子：
9.9
通讯作者：
Wei, Zidong
中科院分区：
文献类型：
--
作者：
Fang, Dahui;Wan, Lei;Wei, Zidong
双金属铂铜（Pt-Cu）合金纳米线由于其固有的高催化活性和耐久性而成为一类新型的燃料电池氧还原反应（ORR）电催化剂，但通过简单的方法制备具有清洁表面的此类电催化剂仍然是一个挑战。本文采用简单的多元醇改性方法，在水/乙二醇（EG）混合介质中通过盐介导的自组装过程制备了具有纳米线网络（NWNs）结构的PtCu合金。系统地研究了PtCu纳米线的形成机制，包括形貌演化和相关实验参数。我们认为，在焦磷酸二氢二钠（Na 2 H2 P2 O 7）的协助下，在H2O-EG介质中形成的微界面及其与Pt 2+或Cu 2+配位的独特性质在NWNs的形成中起着关键作用。当作为ORR催化剂进行测试时，PtCuNWNs/C表现出比PtNWNs/C和商业Pt/C高得多的活性和耐久性，甚至超过了DOE在2020年的目标。PtCuNWNs/C的优异性能归因于NWNs具有2.4nm的波状纳米线和丰富的表面缺陷的独特结构以及Cu原子合金化引起的电子效应的改善。
Bimetallic platinum-copper (Pt-Cu) alloy nanowires have emerged as a novel class of fuel cell electrocatalysts for oxygen reduction reaction (ORR) due to their intrinsic high catalytic activity and durability, but preparing such electrocatalysts with clean surface via facile method is still a challenge. Herein, PtCu alloy with nanowire networks (NWNs) structure is obtained by a simple modified polyol method accompanied with a salt-mediated self-assembly process in a water/ethylene glycol (EG) mixing media. The formation mechanism of PtCu NWNs including the morphological evolution and the relevant experimental parameters has been investigated systematically. We propose that a micro-interface in H2O-EG media formed with the assistance of disodium dihydrogen pyrophosphate (Na2H2P2O7) and its unique nature of coordinating with Pt2+or Cu2+play critical roles in the formation of NWNs. When tested as ORR catalyst, the PtCuNWNs/C exhibits much higher activity and durability than that of PtNWNs/C and commercial Pt/C, even exceeding the target of DOE in 2020. The excellent performance of PtCuNWNs/C could be attributed to the unique structure of NWNs with 2.4 nm ultrathin wavy nanowires and plentiful surface defects and the modified electronic effect caused by alloying with Cu atoms.