Synchrotron X-ray spectroscopy for the local structure analysis of heteroatoms in the zeolite*

  Heteroatom zeolites exhibits a significant modulation of the micropore structure, surface acidity, and particle size depending on the T-site substitution position of the heteroatom, which significantly changes the physical and chemical properties. However, the technology to analyze the accurate atomic position and local structure of heteroatoms introduced into the zeolite framework with complex structures has not been established. These are a challenge for synthesizing truly structure-controlled zeolites.

  Synchrotron X-ray spectroscopy is an analytical method that can provide information on the electronic and local structure of the element of interest. We are applying this technique to zeolites and trying to identify the position of heteroatoms in the zeolite framework. We have prepared metallosilicate, which distributes hetero atoms uniform in intra-framework by mechanochemical (MC) method and synthesized zeolites by hydrothermal synthesis using this metallosilicate as a precursor. In this study, we attempted to understand the mechanism of zeolite synthesis by the MC method from the chemical state and local structure of the heteroatom (Fe) by X-ray absorption and emission spectroscopy.