Dynamic Blocking by CO of Hydrogen Transport across Pd70Au30(110) Surfaces

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• 作者：Shohei OguraKatsuyuki Fukutani
• 刊名：Journal of Physical Chemistry C
• 出版年：2017
• 出版时间：February 16, 2017
• 年：2017
• 卷：121
• 期：6
• 页码：3373-3380
• 全文大小：418K
• ISSN：1932-7455

文摘

CO adsorption affects hydrogen transport across surfaces of hydrogen-absorbing materials. On Pd₇₀Au₃₀(110), CO was found to block the desorption sites for absorbed hydrogen. However, the detailed CO adsorption site and hence the blocking mechanism have not been clarified yet. In this study, we investigated the CO adsorption structure on Pd₇₀Au₃₀(110) by using reflection–absorption infrared spectroscopy (RAIRS). We demonstrate that the CO adsorption structure depends on the CO coverage and sample temperature. We also performed thermal desorption spectroscopy (TDS) simulations on the basis of the RAIRS results and clarified the dynamical mechanism of the CO blocking where the CO site transfer from the Pd on-top to the Pd–Pd bridge sites enhances the blocking efficiency. These discoveries would lead to understanding and controlling the hydrogen transport across the Pd–Au alloy and Pd-related surfaces.