Understanding How in Situ Generated Hydrogen Controls the Morphology of Platinum Nanoparticles

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• 作者：Neus Aguilera-Porta ; Monica Calatayud ; Caroline Salzemann ; Christophe Petit
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：May 1, 2014
• 年：2014
• 卷：118
• 期：17
• 页码：9290-9298
• 全文大小：668K
• 年卷期：v.118,no.17(May 1, 2014)
• ISSN：1932-7455

文摘

Small adsorbed molecules play a key role in the morphology of inorganic nanoparticles. The presence of in situ generated hydrogen during the synthesis of platinum nanoparticles is found to drive the growth of cubic nanocrystals, but little is known about the processes occurring at the molecular level. In this paper, we use standard ab initio calculations to show that hydrogen preferentially adsorbs on (100) Pt facets compared to (111) stabilizing the cubic morphology. Moreover, we provide experimental and theoretical evidence that moderate partial pressure of hydrogen is needed to obtain nanocubes. In the absence of hydrogen, or for low partial pressures, small nanoparticles with undefined shape are formed; however, longer exposure to hydrogen pressure around 1 atm leads to the formation of cubes. Finally, this theoretical result allows presenting an experimental protocol to be used to obtain platinum nanocubes with different degree of truncation.