Reactions of Neutral Platinum Clusters with N2O and CO

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• 作者：Hirotaka Yamamoto ; Ken Miyajima ; Tomokazu Yasuike ; Fumitaka Mafun茅
• 刊名：Journal of Physical Chemistry A
• 出版年：2013
• 出版时间：November 27, 2013
• 年：2013
• 卷：117
• 期：47
• 页码：12175-12183
• 全文大小：433K
• 年卷期：v.117,no.47(November 27, 2013)
• ISSN：1520-5215

文摘

The reduction of N₂O in the gas phase by isolated, neutral platinum clusters, Pt_n (n = 4鈥?2), was investigated using mass spectrometry. The associated oxygen transfer reactions had the general formula Pt_nO_m鈥? + N₂O 鈫?Pt_nO_m + N₂ (m = 1 or 2). The rate constants k₁ and k₂ for the reactions in which m = 1 and 2, respectively, were ascertained and were found to be similar to one another. Unexpectedly, Pt₆O was discovered to be completely unreactive with N₂O under the applied experimental conditions. The reaction mechanism was elucidated on the basis of density functional theory (DFT) calculations, which indicated a reaction barrier between Pt₆O + N₂O and Pt₆O₂ + N₂. The possibility of catalyzing either the reduction of N₂O or the oxidation of CO using neutral Pt_n species was also examined and the results showed that Pt_n does not exhibit significant catalytic properties and that O and CO instead coadsorb to Pt_n. Desorption of CO₂ from the coadsorbed clusters was not clearly identifiable from mass spectra. The reactivities of the platinum clusters were discussed and compared with the properties of the highly catalytically active rhodium clusters.