A XAFS study on the Fe-substituted mordenite

The Fe - substituted mordenite was hydrothermally synthesized and character ized by XRD, FT IR, TPR and XAFS. The FT - IR spectra and powder X - ray di ffraction patterns showed that the as synthesized samples were well crystal line mordenite and the incorporation of Fe into the framework of zeolite wa s verified. The local structure of Fe in the framework was characterized by XAFS. The pre - edge peaks appeared in the XANES spectra of (Si, Fe) - MOR suggested the tetrahedral structure of Fe, and confirmed the incorporation of Fe into the framework of zeolites. The results calculated from the XAFS indicated that the Fe had a tetrahedral structure with an Fe-O distance of 0.188 similar to 0.189nm, which accorded well with the stable structure of as - synthesized zeolites. The peaks at 0.320nm and 0.338nm were assigned to the coordinated Si atoms in the framework.