Development of the dynamical structure analysis method of reaction intermediates by means of time-resolved XAFS

研制了一种可安装在色散XAFS实验系统中的紧凑型反射镜弯曲器和反射镜。反射镜系统用来垂直聚焦光束，降低高阶含量。最初使用的是三角形多色器晶体及其折弯系统，但为了在样品位置实现较小的焦点尺寸，新开发了一种新的矩形多色器晶体和实现椭圆形状的折弯器。对病灶大小进行评估。建立了一套适合于CCD探测器动力学模型的耦合光学系统。众所周知，CuZSM-5催化剂对NO分解具有独特的催化性能，其活性与铜物种的氧化还原反应有关。利用自行研制的1s能量色散XAFS系统，研究了程序升温还原(300-700K)过程中铜离子在ZSM-5中的时间分辨还原过程。时间分辨率。通道中孤立的Cu2+和Gt；物种逐渐减少。在400-450K时，它们被还原为孤立的Cu2+物种，然后在550-650K时，它们被还原为Cu0金属团簇。在还原过程中，有一小部分分子进入ZSM-5分子筛的外表面，并用旋转流动仪进行了溶液反应的初步实验。实践证明，使用本研究开发的系统可以获得较高质量的数据。

A compact mirror bender and a mirror, which can be installed in a dispersive XAFS experimental system, were developed. The mirror system is used to focus the beam vertically and reduce the higher order content. Triangular polychomator crystals and the bender system for it was used at first, but a new rectangular polychromator crystal and a bender to realize elliptical shape is newly developed in order to achieve smaller focus size at the sample position. The focus sizes were evaluated. A coupling optics system to meet the requirement of kinetics mode of a CCD detector is also developed.Cu-ZSM-5 catalyst is well known that it has unique catalytic property for NO decomposition and its activity is related to the redox reaction of copper species. The time resolved reduction process of copper cations in ZSM-5 during temperature-programmed reduction (300-700K) was studied by using the energy-dispersive XAFS system developed in this research with 1 sec. time-resolution. The isolated Cu^<2+> species in the channel were reduced stepwise. They were reduced to isolated Cu^+ species at 400-450 K, then to Cu^0 metallic clusters at 550-650K.Small clusters like Cu_4 were initially formed, followed by particle growth. A small part of them went out to the outer surfaces of ZSM-5 during the reduction.Preliminary experiment of solution reaction by using sropped-flow apparatus was also carried out. It is confirmed that fairly high quality data can be obtained by using the system developed in this research.