Structure of the Novel Large Pore Gallosilicate TNU-7

Abstract

The Structure of a novel large pore gallosilicate zcolite, TNU-7, has been refined from X-ray powder diffraction data. The silicate framework is built Lip from two different types of layer which are shown by X-ray and electron diffraction to be arranged in a fully ordered way. This gives rise to 12-MR pores and asymmetric cation distributions. TNU-7 is prepared hydrothemally over a very narrow compositional range and only in the presence of Ga. Other zeolitic phases crystallise at lower and higher Ga contents confirming the unique structure-directing ability of this element. The location of ion exchanged Cs+ and Sr2+ cations in TNU-7 has been Studied by high resolution X-ray powder diffraction.