Ambient pressure X-ray absorption spectroscopy at ME2-BL02B of SSRF and its application in catalysis [上海光源ME2-BL02B实验站近常压X射线吸收谱方法及在催化中的应用]

作者：Wang W.; Li X.; Peng Z.; Zhang N.; Zhang H.; Liu Z.

来源：Nuclear Techniques, 2021, 44(9): 090101.

DOI：10.11889/j.0253-3219.2021.hjs.44.090101

• Ambient pressure
• Electron yield mode
• in situ
• Surface catalysis
• X-ray absorption spectroscopy

Background: The traditional soft X-ray absorption spectroscopy (XAS) method can only work under ultra-high vacuum conditions and cannot be used to detect changes in the electronic structure of samples under real conditions. However, the in-situ soft X-ray absorption spectroscopy method developed in the past decade is mainly based on the fluorescence yield mode. The lack of surface sensitive electron yield mode XAS, especially the Auger electron yield mode, hinders effective detection of chemical information and electronic structure changes on the surface. Purpose: This study aims to investigate the near-ambient pressure X-ray absorption spectroscopy method and the chemical information of the sample surface in the real state. Methods: By constructing the communication between electron energy spectrometer and the monochromator, the near-atmospheric soft X-ray absorption spectroscopy setup and method were developed at the ME2-BL02B terminal station of Shanghai Synchrotron Radiation Facility (SSRF) different modes of X-ray absorption spectrum under in-situ conditions could be measured in this terminal station, including total electron yield, partial electron yield, and Auger electron yield mode. With the help of in-situ method, the dynamic surface changes of materials at different depths could be described, and platinum-titanium dioxide catalyst for CO oxidation was selected as an example. Results: The in-situ ambient pressure X-ray absorption spectroscopy of the electron yield mode recently developed at the ME2-BL02B terminal of SSRF is successfully applied to investigating the catalyst surface under real conditions, and experimental results show the superiority of the surface-sensitive XAS method. Conclusions: The ambient pressure X-ray absorption spectroscopy method of this study can be used to approximate the chemical information changes of samples in real environments, thereby providing powerful tools for users in the fields of catalysis, environment and energy.

• 单位
  中国科学院大学; 信息功能材料国家重点实验室