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  

Ambient pressure X-ray absorption spectroscopy at ME2-BL02B of SSRF and its application in catalysis

作　　者：汪威 李小宝 彭蒸 张念 章辉 刘志 WANG Wei;LI Xiaobao;PENG Zheng;ZHANG Nian;ZHANG Hui;LIU Zhi(State Key Laboratory of Functional Materials for Informatics,Shanghai Institute of Microsystem and Information Technology,Chinese Academy of Sciences,Shanghai 200050,China;University of Chinese Academy of Sciences,Beijing 100049,China;School of Physical Science and Technology,ShanghaiTech University,Shanghai 201210,China)

机构地区：[1]中国科学院上海微系统与信息技术研究所信息功能材料国家重点实验室,上海200050 [2]中国科学院大学,北京100049 [3]上海科技大学物质科学与技术学院,上海201210

出　　处：《核技术》2021年第9期1-10,共10页Nuclear Techniques

基　　金：国家自然科学基金(No.11227902、No.21902179)资助。

摘　　要：传统的软X射线吸收谱方法只能在超高真空条件下工作,从而无法用于探测真实条件下样品的电子结构变化。而近十年来发展的原位工况条件下的软X射线吸收谱方法主要是基于荧光产额模式,而缺乏具有表面灵敏特性的电子产额模式,特别是俄歇电子产额模式,这阻碍了对表面的化学信息和电子结构变化有效的探测。为了研究真实反应状态下样品表面的化学信息,最近在上海光源ME2-BL02B实验站发展的近常压X射线吸收谱方法可以对这一问题提出解决方案。通过该实验站的近常压软X射线吸收谱装置和方法,实验站可实现原位条件下不同模式的吸收谱采集(包括全电子产额、部分电子产额和俄歇电子产额模式),从而在不同深度上描述材料的表面的动态变化。以铂-二氧化钛样品为例,给出表面灵敏的X射线吸收谱方法的优越性。研究结果表明:近常压X射线吸收谱方法可以用于表征接近真实反应环境下样品表面的化学信息变化,从而为催化、环境和能源等研究领域的用户提供强有力的原位表征手段。[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.

关 键 词：近常压 原位 X射线吸收谱 电子产额模式 表面催化 

分 类 号：O647[理学—物理化学]