Pd‐Ru Alloy Nanocages with a Face‐Centered Cubic Structure and Their Enhanced Activity toward the Oxidation of Ethylene Glycol and Glycerol
Pd‐Ru Alloy Nanocages with a Face‐Centered Cubic Structure and Their Enhanced Activity toward the Oxidation of Ethylene Glycol and Glycerol
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DOI：
10.1002/smtd.201900843
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发表时间：
2020-05
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通讯作者：
Ming Zhao;Zhiheng Lyu;Minghao Xie;Zachary D. Hood;Zhenming Cao;M. Chi;Younan Xia
中科院分区：
文献类型：
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作者：
Ming Zhao;Zhiheng Lyu;Minghao Xie;Zachary D. Hood;Zhenming Cao;M. Chi;Younan Xia
本文报道了一种通过激活Pd纳米晶体与Ru（III）前体之间的电流置换反应来合成Pd-Ru纳米笼的简便方法。合成的纳米笼具有中空的内部，厚度为2.5 nm的纳米壁和立方体形状。我们的定量研究表明，Ru（III）前体的还原速率可以在I-离子的引入后大大加速，然后随着I-/Ru 3+的比例增加而减慢。Pd-Ru纳米笼采用合金结构，纳米笼中的Ru原子以面心立方结构结晶，而不是块状Ru所采用的六方密堆积相。使用具有不同边长的Pd纳米立方体，纳米笼的尺寸在6 - 18 nm范围内可以容易地调节。当分别作为乙二醇和甘油的电氧化催化剂进行测试时，由18 nm Pd立方体制备的Pd-Ru立方体纳米笼相对于商业Pd/C在质量活性方面表现出5.1和6.2倍的增强。经过1000次循环的加速耐久性测试，纳米笼的质量活性仍然分别是原始商业Pd/C催化剂的3.3和3.7倍。
This article reports a facile method for the synthesis of Pd‐Ru nanocages by activating the galvanic replacement reaction between Pd nanocrystals and a Ru(III) precursor with I‐ions. The as‐synthesized nanocages feature a hollow interior, ultrathin wall of ≈2.5 nm in thickness, and a cubic shape. Our quantitative study suggests that the reduction rate of the Ru(III) precursor can be substantially accelerated upon the introduction of I‐ions and then retarded as the ratio of I‐/Ru3+is increased. The Pd‐Ru nanocages take an alloy structure, with the Ru atoms in the nanocages crystallized in a face‐centered cubic structure instead of the hexagonal close‐packed phase taken by bulk Ru. Using Pd nanocubes with different edge lengths, the dimensions of the nanocages in the range of 6−18 nm can readily be tuned. When tested as catalysts toward the electro‐oxidation of ethylene glycol and glycerol, respectively, the Pd‐Ru cubic nanocages prepared from 18 nm Pd cubes exhibit 5.1‐ and 6.2‐fold enhancements in terms of mass activity relative to the commercial Pd/C. After 1000 cycles of accelerated durability test, the mass activities of the nanocages are still 3.3 and 3.7 times as high as that of the pristine commercial Pd/C catalyst, respectively.