A Pathway for the Growth of Core鈥揝hell Pt鈥揚d Nanoparticles

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• 作者：Chaitanya K. Narula ; Xiaofan Yang ; Chen Li ; Andrew R. Lupini ; Stephen J. Pennycook
• 刊名：Journal of Physical Chemistry C
• 出版年：2015
• 出版时间：November 5, 2015
• 年：2015
• 卷：119
• 期：44
• 页码：25114-25121
• 全文大小：604K
• ISSN：1932-7455

文摘

The aging of both Pt鈥揚d nanoparticles and core鈥搒hell Pt鈥揚d nanoparticles has been reported to result in alloying of Pt with Pd. In comparison to monometallic Pt catalysts, the growth of Pd鈥揚t bimetallics is slower; however, the mechanism of growth of particles and the mechanism by which Pd improves the hydrothermal durability of bimetallic Pd鈥揚t particles remains uncertain. In our work on hydrothermal aging of core鈥搒hell Pt鈥揚d nanoparticles, synthesized by solution methods, with varying Pd:Pt ratio of 1:4, 1:1, and 4:1, we compare the growth of core鈥搒hell Pt鈥揚d nanoparticles and find that particles grow by migrating and joining together. The unique feature of the observed growth is that Pd shells from both particles open up and join, thereby allowing the cores to merge. At high temperatures, alloying occurs in good agreement with reports by other workers.