Pt-Based Icosahedral Nanocages: Using a Combination of {111} Facets, Twin Defects, and Ultrathin Walls to Greatly Enhance Their Activity toward Oxygen Reduction,Nano Letters

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Pt-Based Icosahedral Nanocages: Using a Combination of {111} Facets, Twin Defects, and Ultrathin Walls to Greatly Enhance Their Activity toward Oxygen Reduction
Nano Letters ( IF 9.6 ) Pub Date : 2016-01-15 00:00:00 , DOI: 10.1021/acs.nanolett.5b05140
Xue Wang _{1,

2} , Legna Figueroa-Cosme ₃ , Xuan Yang ₁ , Ming Luo ₁ , Jingyue Liu ₄ , Zhaoxiong Xie ₂ , Younan Xia _{1,

3}

Affiliation

Engineering the surface structure of noble-metal nanocrystals offers an effective route to the development of catalysts or electrocatalysts with greatly enhanced activity. Here, we report the synthesis of Pt-based icosahedral nanocages whose surface is enclosed by both {111} facets and twin boundaries while the wall thickness can be made as thin as six atomic layers. The nanocages are derived from [email protected]_4.5L icosahedra by selectively etching away the Pd in the core. During etching, the multiply twinned structure can be fully retained whereas the Pt atoms in the wall reconstruct to eliminate the corrugated structure built in the original Pt shell. The Pt-based icosahedral nanocages show a specific activity of 3.50 mA cm^–2 toward the oxygen reduction reaction, much greater than those of the Pt-based octahedral nanocages (1.98 mA cm^–2) and a state-of-the-art commercial Pt/C catalyst (0.35 mA cm^–2). After 5000 cycles of accelerated durability test, the mass activity of the Pt-based icosahedral nanocages drops from 1.28 to 0.76 A mg^–1_Pt, which is still about four times greater than that of the original Pt/C catalyst (0.19 A mg^–1_Pt).

中文翻译：

铂基二十面体纳米笼：使用{111}面，双缺陷和超薄壁的组合极大地增强了它们的减氧活性

对贵金属纳米晶体的表面结构进行工程设计为开发具有大大增强的活性的催化剂或电催化剂提供了一条有效途径。在这里，我们报告了基于Pt的二十面体纳米笼的合成，其表面被{111}晶面和孪晶边界包围，而壁厚可以薄至6个原子层。纳米笼通过选择性蚀刻掉核心中的Pd而从[电子邮件保护的] _4.5L二十头蛇衍生而来。在蚀刻过程中，多重孪晶结构可以完全保留，而壁中的Pt原子可以重建，从而消除了原始Pt壳中的波纹结构。基于Pt的二十面体纳米笼显示的比活度为3.50 mA cm ^–2在氧还原反应方面，它远远大于基于Pt的八面体纳米笼（1.98 mA cm ^–2）和最先进的商用Pt / C催化剂（0.35 mA cm ^–2）。经过5000次加速耐久性测试，基于Pt的二十面体纳米笼的质量活性从1.28降至0.76 A mg ^–1_Pt，仍比原始Pt / C催化剂（0.19 A mg ^{– 1}_的Pt）。

更新日期：2016-01-15

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