(96h) A Full Understanding of Microporous Vanadosilicate AM-6: The Crystal Quality and Structure of AM-6

Microporous vanadosilicate AM-6, isostructural with titanosilicate ETS-10, is a novel promising material in the traditional zeolite applications such as catalysis, photocatalysis, gas separation, sorption and the monatomic –O-V-O-V-O chains have shown potential for use in quantum wire application. High purity vanadosilicate AM-6 products with different crystal quality (disorder, or average length of the V-O-V chains in the AM-6 framework) and sizes in the range of ~50 nm to ~6 were hydrothermally synthesized at 448-503 K using tetramethylammonium (TMA⁺) ions. The sizes of crystals were coincided with average crystal size calculated from Scherrer and Williamson-Hall approaches using line broadening measured at half its maximum intensity. The combined SEM, EDX, XRD, Raman, TGA, XPS, and nitrogen adsorption isotherm data showed that by treating these as-synthesized materials in gaseous ammonia at 673 K it is possible to completely remove TMA⁺ ions from the AM-6 pores without adversely affecting product crystallinity and the micropore structure of AM-6, and with only minimal degradation of crystal quality of the resulting products. However, the success in a complete removal of TMA⁺ ions without affecting other crystalochemical characteristics of the product depended on its initial crystal quality.