Structural studies of hydrated germanium X-type zeolite via Rietveld analysis of synchrotron powder X-ray diffraction data

An aluminogermanate analog of zeolite X has been synthesized by solution reaction, and characterized by Rietveld analysis of synchrotron powder X-ray diffraction data. The hydrated sample has a chemical formula Na₉₆Al₉₆Ge₉₆O₃₈₄·wH ₂O, and the material possesses an ordered arrangement of Al and Ge in the framework. A cell parameter of 25.589(1)Å confirms the expected cell expansion over Low Silica X (LSX), although a smaller average framework T-O-T bond angle indicates greater relative cell collapse than for LSX. The distribution of sodium cations in the non-framework sites in NaGeX is significantly different from that in LSX, and appears to deviate from the proposed relationship between Al content and cation siting for hydrated aluminosilicate faujasite-type zeolites.