How to Remove the Capping Agent from Pd Nanocubes without Destructing Their Surface Structure for the Maximization of Catalytic Activity?
How to Remove the Capping Agent from Pd Nanocubes without Destructing Their Surface Structure for the Maximization of Catalytic Activity?
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DOI：
10.1002/anie.202006011
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发表时间：
2020-08-26
影响因子：
16.6
通讯作者：
Xia, Younan
中科院分区：
文献类型：
--
作者：
Shi, Yifeng;Lyu, Zhiheng;Xia, Younan
我们报道了一种有效去除Pd纳米立方体表面化学吸附的Br（-）离子（一种封端剂）以最大限度地提高其催化活性的方法。Br（-）离子可以通过简单地在水中加热样品来去除，但是Br（-）离子的解吸将使下面的Pd原子暴露于来自空气的O（2），以形成相对厚的氧化物层。在电位循环过程中，氧化层演变成有害的特征，如台阶和梯田。通过向体系中引入微量肼，可以通过加热去除Br（-）离子而不形成厚的氧化物层。清洗后的纳米立方体显示出极大增强的活性对甲酸氧化。这种清洁方法也可以从Rh纳米立方体中去除Br（-）离子，并且预期其适用于纳米晶体和封端剂的其他组合。
We report a robust method for effectively removing the chemisorbed Br(-)ions, a capping agent, from the surface of Pd nanocubes to maximize their catalytic activity. The Br(-)ions can be removed by simply heating the sample in water, but the desorption of Br(-)ions will expose the underneath Pd atoms to the O(2)from air for the formation of a relatively thick oxide layer. During potential cycling, the oxide layer evolves into detrimental features such as steps and terraces. By introducing a trace amount of hydrazine into the system, the Br(-)ions can be removed by heating without forming a thick oxide layer. The as-cleaned nanocubes show greatly enhanced activity toward formic acid oxidation. This cleaning method can also remove Br(-)ions from Rh nanocubes and it is expected to work for other combinations of nanocrystals and capping agents.