Watching Nanoparticles Grow: The Mechanism and Kinetics for the Formation of TiO2-Supported Platinum Nanoparticles

详细信息    查看全文

• 作者：Peter J. Chupas ; Karena W. Chapman ; Guy Jennings ; Peter L. Lee ; Clare P. Grey
• 刊名：Journal of the American Chemical Society
• 出版年：2007
• 出版时间：November 14, 2007
• 年：2007
• 卷：129
• 期：45
• 页码：13822 - 13824
• 全文大小：276K
• 年卷期：v.129,no.45(November 14, 2007)
• ISSN：1520-5126

文摘

The formation of supported Pt nanoparticles during the reduction of Pt⁴⁺ on TiO₂ under H₂ (4% in He) gas flow has been monitored using a differential approach to time-resolved pair distribution function (PDF) analysis of high-energy X-ray scattering data. The reduction of Pt⁴⁺ species was found to follow pseudo-zero-order reaction kinetics, with an activation energy of 0.52 eV. Reaction data obtained at constant temperature (100, 150, and 200 C) and during heating (0-200 C) indicate that the growth of nanoparticles from the reduce Pt⁰ species depends strongly on temperature and proceeds more rapidly upon heating.